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.

What is the purpose of the text above?

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. The lower temperature reduces the reproduction rate of bacteria and prolongs the lifetime of the food.

b. A refrigerator ( also called a fridge ) is a common household appliance.

c. It has an electrical thermal component that is able to lower the temperature.

d. It is used to store food to keep it fresh for later cooking.

The best arrangement to make a good paragraph is . . .

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?

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.

At the workshop or repair shops, the mechanic puts on glasses to....

The Shard is an 87-storey skyscraper, which sits in the heart of London. It is known as the shard of glass. Construction began in 2009 and was completed three years later in 2012, making it Western Europe’s tallest building.

Designed by architect Renzo Piano, The Shard is the second tallest free standing structure in the UK. Its exterior boasts 11,000 glass panels – that’s equivalent in area to eight football pitches or two-and-a-half Trafalgar Squares.

The building was developed to have multiple uses, describes on the website as a ‘vertical city where people can live, work and relax’. This motto was clearly taken on board that was found on the 72nd floor towards the end of construction.

What is the text about?