A scientist is conducting a study to determine how well a new medication treats ear infections. The scientist tells the participants to put 10 drops in their infected ear each day. After two weeks, all participants' ear infections had healed.

Which of the following changes to the design of this study would most improve the ability to test if the new medication effectively treats ear infections?

Which of the following is an example of genetic engineering?

What is the main cause of seasons on the Earth?

These graphs show the monthly precipitation and average temperature for three cities in the United States over the course of one year. Based on the graphs, which city has the greatest annual range of temperatures?

The time a computer takes to start has increased dramatically. One possible explanation for this is that the computer is running out of memory.

This explanation is a scientific …

Many diseases have an incubation period. Which of the following best describes what an incubation period is?

When large areas of forest are removed so land can be converted for other uses, such as farming, which of the following occurs?

An antacid relieves an overly acidic stomach because the main components of antacids are …

Which of these is a major concern about the overuse of antibiotics?

A car travels at a constant speed of 40 miles per hour. How far does the car travel in 45 minutes?

How many teeth does an adult human have?

The Earth has three layers of varying temperatures. What are these three basic layers?

What is the rarest major blood type?

What is the boiling point of water?

Which scientist proposed three laws of motion?

Animals active during dawn and dusk are known as:

This animal has fingerprints that are impossible to differentiate from human fingerprints.

What did Alfred Nobel invent?

What is it called when solid matter transitions to a gas immediately, without transitioning through a liquid state?

According to Apollo astronauts, the Moon smells like:

This plant is a relative of poison ivy and can cause skin irritation:

In studies of public restrooms, this stall has been found to have the least amount of germs:

What color is human blood inside veins?

What is the rarest naturally-occurring element?

If you expose a glass of water to outer space, it will:

The hardest chemical in your body:

There is enough salt in the world's oceans to cover all of the continents' land with _____ feet of salt.

This metal will melt in the palm of your hand.

In a 200 pound adult, 2-6 pounds of body weight is from:

Orcas are the largest species of

When Betelgeuse explodes in a luminous supernova (any day now), it will light up our skies for

Someday, our galaxy (the Milky Way) will merge with this galaxy:

This is the largest known star in the universe, a hypergiant with a radius around 1,700 times larger than the Sun

This group of elements is the least reactive

To view this scientist's radioactive manuscripts, all guests must sign a liability waiver and wear protective gear.

If you took out the empty space from all of the atoms that make up every person, the volume of all of humanity would fit into a space comparable to:

These planets have retrograde motion (they rotate counterclockwise instead of clockwise)

This human organ was "discovered" in 2017 (technically it was just reclassified as a separate organ)

This microcontinent broke away from Antarctica 100 million years ago and is currently 93% submerged underwater.

Human DNA consists of about _____ base pairs

Who invented the microchip?

The most reactive group of elements

According to the "giant-impact hypothesis" of Moon formation, it is thought that this planet collided with Earth about 4.5 billion years ago.

The oldest known fossil of Homo sapiens is a 300,000 year old skull found in ____.

One of the oldest non-clonal, non-colonial organisms on Earth is Methuselah, a 4,851 year old: