15 questions
Oil, natural gas and coals are examples of...
Biofuels
Geothermal resources
Renewable resources
Fossil fuels
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?
Have participants use ear drops for only one week
Create a separate group of participants who use 15 ear drops a day
Create a separate group of participants with ear infections who do not use any ear drops
Have participants put ear drops in both their infected ear and their healthy ear
Which of the following is an example of genetic engineering?
Growing a whole plants from a single cell
Attaching the root of one type of plant to the stem of another type of plant
Finding the sequences of bases in plant DNA
Inserting a gene into plants that makes them resistant to insects
What is the main cause of seasons on Earth?
The distance between the Earth and the sun
The speed that the Earth rotates around the sun
The tilt of the Earth's axis in relation to the sun
Changes in the amount of energy coming from the sun
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?
Chicago, Illinois
New York, New York
Los Angeles, California
They all have the same annual temperature range
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 …
Experiment
Conclusion
Observation
Hypothesis
Many diseases have an incubation period. Which of the following best describes what an incubation period is?
The period during which someone builds up immunity to a disease
The period during which someone has an infection, but is not showing symptoms
The effect of a disease on babies
The recovery period after being sick
When large areas of forest are removed so land can be converted for other uses, such as farming, which of the following occurs?
Greater oxygen production
Colder temperature
Decreased carbon dioxide
Increased erosion
An antacid relieves an overly acidic stomach because the main components of antacids are …
Isotopes
Acids
Bases
Neutral
Which of these is a major concern about the overuse of antibiotics?
It can lead to antibiotic-resistant bacteria
There will be an antibiotic shortage
Antibiotics can cause secondary infections
Antibiotics will get into the water systems
A car travels at a constant speed of 40 miles per hour. How far does the car travel in 45 minutes?
25 miles
30 miles
35 miles
40 miles
Which of these planets is closest to Earth?
Venus
Saturn
Neptune
Jupiter
What is the most abundant element in the Earth's crust?
Oxygen
Silicon
Iron
Aluminum
What type of waves do cellphones use?
Mircowaves
Radio waves
Light waves
Tidal waves
A hair dryer changes electrical energy into what type of energy?
Kinetic energy
Friction
Thermal energy
Mechanical energy