An electronic calculator is a small, portable electronic device used to perform both arithmetic operations and complex mathematical operations.

The first solid electronic calculator was created in the 1960s, building on the extensive history of tools such as the abacus (developed around 2000 BC), and the mechanical calculator (developed in the 17^th century AD). It was developed in parallel with the analog computers of the day.

In addition to general purpose of calculators, there are those designed for specific markets, for example, there are scientific calculators which include trigonometric and statistical calculations. Some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, or higher dimensional Euclidean space.

When does the mechanical calculator developed?

An electronic calculator is a small, portable electronic device used to perform both arithmetic operations and complex mathematical operations.

The first solid electronic calculator was created in the 1960s, building on the extensive history of tools such as the abacus (developed around 2000 BC), and the mechanical calculator (developed in the 17^th century AD). It was developed in parallel with the analog computers of the day.

In addition to general purpose of calculators, there are those designed for specific markets, for example, there are scientific calculators which include trigonometric and statistical calculations. Some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, or higher dimensional Euclidean space.

What is the meaning of “extensive” in the second paragraph?

An electronic calculator is a small, portable electronic device used to perform both arithmetic operations and complex mathematical operations.

The first solid electronic calculator was created in the 1960 s, building on the extensive history of tools such as the abacus (developed around 2000 BC), and the mechanical calculator (developed in the 17^th century AD). It was developed in parallel with the analog computers of the day.

In addition to general purpose of calculators, there are those designed for specific markets, for example, there are scientific calculators which include trigonometric and statistical calculations. Some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, or higher dimensional Euclidean space.

It was developed in parallel with the analog computers of the day. The underlined word refers to ...

An electronic calculator is a small, portable electronic device used to perform both arithmetic operations and complex mathematical operations.

The first solid electronic calculator was created in the 1960s, building on the extensive history of tools such as the abacus (developed around 2000 BC), and the mechanical calculator (developed in the 17^th century AD). It was developed in parallel with the analog computers of the day.

In addition to general purpose of calculators, there are those designed for specific markets, for example, there are scientific calculators which include trigonometric and statistical calculations. Some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, or higher dimensional Euclidean space.

What is the main idea of paragraph 3?

A laptop is a kind of computer unit which has the same function as a PC (Personal Computer), but it’s smaller, lighter and of different sizes. Nowadays, most people choose laptops for several reasons.

A laptop is a portable device. This portability is very helpful for our work, study and other activities. We do not need complicated cable installations to activate a laptop. With a laptop, we can do our work anytime and anywhere.

Moreover, a laptop allows us to access the internet in public places which provide free access called hot spot areas. Some people like to use this facility to carry out their tasks.

Finally, a laptop consumes energy more efficiently than a PC does. This device uses a rechargeable battery as a source of electric energy. So, if we prefer using a laptop, it means that we support the government program to save energy. That’s why a laptop has become very popular recently.

A public place where we can have free access to the internet is …

A laptop is a kind of computer unit which has the same function as a PC (Personal Computer), but it’s smaller, lighter and of different sizes. Nowadays, most people choose laptops for several reasons.

A laptop is a portable device. This portability is very helpful for our work, study and other activities. We do not need complicated cable installations to activate a laptop. With a laptop, we can do our work anytime and anywhere.

Moreover, a laptop allows us to access the internet in public places which provide free access called hot spot areas. Some people like to use this facility to carry out their tasks.

Finally, a laptop consumes energy more efficiently than a PC does. This device uses a rechargeable battery as a source of electric energy. So, if we prefer using a laptop, it means that we support the government program to save energy. That’s why a laptop has become very popular recently.

A laptop has become very popular because …

A laptop is a kind of computer unit which has the same function as a PC (Personal Computer), but it’s smaller, lighter and of different sizes. Nowadays, most people choose laptops for several reasons.

A laptop is a portable device. This portability is very helpful for our work, study and other activities. We do not need complicated cable installations to activate a laptop. With a laptop, we can do our work anytime and anywhere.

Moreover, a laptop allows us to access the internet in public places which provide free access called hot spot areas. Some people like to use this facility to carry out their tasks.

Finally, a laptop consumes energy more efficiently than a PC does. This device uses a rechargeable battery as a source of electric energy. So, if we prefer using a laptop, it means that we support the government program to save energy. That’s why a laptop has become very popular recently.

“ …a laptop allows us….” (paragraph 1 line 1)

The underlined word has the opposite meaning with …

A laptop is a kind of computer unit which has the same function as a PC (Personal Computer), but it’s smaller, lighter and of different sizes. Nowadays, most people choose laptops for several reasons.

A laptop is a portable device. This portability is very helpful for our work, study and other activities. We do not need complicated cable installations to activate a laptop. With a laptop, we can do our work anytime and anywhere.

Moreover, a laptop allows us to access the internet in public places which provide free access called hot spot areas. Some people like to use this facility to carry out their tasks.

Finally, a laptop consumes energy more efficiently than a PC does. This device uses a rechargeable battery as a source of electric energy. So, if we prefer using a laptop, it means that we support the government program to save energy. That’s why a laptop has become very popular recently.

From the text we know that ….

A camera is an optical instrument for recording images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies. The functioning of the camera is very similar to the functioning of the human eye.

A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene, and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens and an image is recorded on a light-sensitive medium.

A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim.

A movie camera or a video camera operates similarly to a still camera, except it records a series of static images in rapid succession, commonly at a rate of 24 frames per second. When the images are combined and displayed in order, the illusion of motion is achieved.

What kind of text is it?

A camera is an optical instrument for recording images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies. The functioning of the camera is very similar to the functioning of the human eye.

A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene, and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens and an image is recorded on a light-sensitive medium.

A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim.

A movie camera or a video camera operates similarly to a still camera, except it records a series of static images in rapid succession, commonly at a rate of 24 frames per second. When the images are combined and displayed in order, the illusion of motion is achieved.

What is the purpose of this text?

A camera is an optical instrument for recording images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies. The functioning of the camera is very similar to the functioning of the human eye.

A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene, and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens and an image is recorded on a light-sensitive medium.

A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim.

A movie camera or a video camera operates similarly to a still camera, except it records a series of static images in rapid succession, commonly at a rate of 24 frames per second. When the images are combined and displayed in order, the illusion of motion is achieved.

The function of camera is described in paragraph …

A camera is an optical instrument for recording images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies. The functioning of the camera is very similar to the functioning of the human eye.

A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene, and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens and an image is recorded on a light-sensitive medium.

A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim.

A movie camera or a video camera operates similarly to a still camera, except it records a series of static images in rapid succession, commonly at a rate of 24 frames per second. When the images are combined and displayed in order, the illusion of motion is achieved.

From the text, we know that …

A camera is an optical instrument for recording images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies. The functioning of the camera is very similar to the functioning of the human eye.

A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene, and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens and an image is recorded on a light-sensitive medium.

A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim.

A movie camera or a video camera operates similarly to a still camera, except it records a series of static images in rapid succession, commonly at a rate of 24 frames per second. When the images are combined and displayed in order, the illusion of motion is achieved.

The word rapid in par.4 has similar meaning like…

Bicycles are human powered vehicles, typically featuring pedals, a seat, two wheels and a frame. Before the word ‘bicycle’ become popular (coming from the French word ‘bicyclette’), bikes were typically called ‘velocipedes’.

Bicycles are used for transport, recreation, competitive racing, courier delivery and a range of other tasks.

Bicycles typically use a chain to transmit power to the rear wheel. Some bicycles feature suspension. This is especially common in mountain bikes where they are used to help deal with the vibration caused by uneven surfaces. Road bikes typically have thinner tires inflated to higher pressures than those found on mountain bikes, taking advantage of the smoother surfaces that roads generally provide.

What is the text about?

Bicycles are human powered vehicles, typically featuring pedals, a seat, two wheels and a frame. Before the word ‘bicycle’ become popular (coming from the French word ‘bicyclette’), bikes were typically called ‘velocipedes’.

Bicycles are used for transport, recreation, competitive racing, courier delivery and a range of other tasks.

Bicycles typically use a chain to transmit power to the rear wheel. Some bicycles feature suspension. This is especially common in mountain bikes where they are used to help deal with the vibration caused by uneven surfaces. Road bikes typically have thinner tires inflated to higher pressures than those found on mountain bikes, taking advantage of the smoother surfaces that roads generally provide.

We know from the text that people use bicycles for ................................., except;

Computers are machines that handle information automatically. They can perform calculations and process data. Computers can work with numbers to solve problems in a few seconds. Computer can remember a great deal of information and make practically no mistakes. That is why computers are used in places such as banks, offices and companies.

Computers work like calculators. But most calculators can do only one thing at a time. we tell them what to do by pressing buttons so that it processes, we can give a series of instructions to a computer. Other information such as a list, numbers, letters, words or even graphs or pictures. Once we provide a programme, the computer can do all this work automatically without further help or instruction.

A computer stores and handles number. The numbers may be mathematical formulas or numbers in columns of figures. Numbers can also be codes that stand for letters of the alphabet, words or instructions to the computer.

A computer stores and handles number( Paragraph 3). The word “ stores” has the same meaning with......

Computers are machines that handle information automatically. They can perform calculations and process data. Computers can work with numbers to solve problems in a few seconds. Computer can remember a great deal of information and make practically no mistakes. That is why computers are used in places such as banks, offices and companies.

Computers work like calculators. But most calculators can do only one thing at a time. we tell them what to do by pressing buttons so that it processes, we can give a series of instructions to a computer. Other information such as a list, numbers, letters, words or even graphs or pictures. Once we provide a programme, the computer can do all this work automatically without further help or instruction.

A computer stores and handles number. The numbers may be mathematical formulas or numbers in columns of figures. Numbers can also be codes that stand for letters of the alphabet, words or instructions to the computer.

This Machine works automatically, it does not …….. an operator.

Computers are machines that handle information automatically. They can perform calculations and process data. Computers can work with numbers to solve problems in a few seconds. Computer can remember a great deal of information and make practically no mistakes. That is why computers are used in places such as banks, offices and companies.

Computers work like calculators. But most calculators can do only one thing at a time. we tell them what to do by pressing buttons so that it processes, we can give a series of instructions to a computer. Other information such as a list, numbers, letters, words or even graphs or pictures. Once we provide a programmer, the computer can do all this work automatically without further help or instruction.

A computer stores and handles number. The numbers may be mathematical formulas or numbers in columns of figures. Numbers can also be codes that stand for letters of the alphabet, words or instructions to the computer.

Why are computers used in Banks, in public and private offices?

Glasses—also called eyeglasses (formal), spectacles, or specs (informal)—are frames bearing lenses worn in front of the eyes, normally for vision correction or eye protection. Safety glasses are kind of eye protection against flying debris or against visible and near visible light or radiation. Sunglasses allow better vision in bright daylight, and may protect against damage from high levels of ultraviolet light. Other types of glasses may be used for viewing visual information (such as stereoscope) or simply just for aesthetic or fashion values.

Historical types of glasses include the pincers, monocle, lorgnette, and scissors or scissors-glasses.

Modern glasses are typically supported by pads on the bridge of the nose and by temple arms (sides) placed over the ears. CR-39 lenses are the most common plastic lenses due to their low weight, high scratch resistance, low dispersion, and low transparency to ultraviolet and infrared radiation. Polycarbonate and Trivex lenses are the lightest and most shatter-resistant, making them the best for impact protection.

An unpopular aspect of glasses is their inconvenience. Even through the creation of light frames such as those made of titanium, very flexible frames and new lens materials and optical coatings, glasses can still cause problems during rigorous sport, Visibility can be significantly reduced by becoming greasy, trapping vapour when eating hot food, swimming, walking in rain or rapid temperature changes (such as walking into a warm building from cold temperature outside). Scraping, fracturing, or breakage of the lenses require time—consuming and costly professional repair, though modern plastic lenses are almost indestructible and very scratch—resistant.

What is one good point of CR – 39 lenses?