Question: Choose your answer.

Which is the best explanation for how air masses move across the United States?

OPTIONS:
- The prevailing westerlies move air masses from west to east across the United States but may be deflected by the jet stream.
- The trade winds move air masses from west to east across the United States.
- The jet stream moves air masses from the Pacific Ocean across the United States.
- The warm air of the Gulf Stream causes air masses to move from the Atlantic Ocean to the Pacific Ocean.
My Answer: The prevailing westerlies move air masses from west to east across the United States but may be deflected by the jet stream.

Question: Choose your answer.

Scientists claim that the continents of South America and Africa were once a single landmass. All of the following observations support this claim except

OPTIONS:
- the mountains on these continents have similar rocks of the same age.
- these continents appear to fit together like the pieces of a puzzle.
- similar fish live in the ocean off the coasts of these continents.
- the same kinds of fossils have been found on these continents.
My Answer: similar fish live in the ocean off the coasts of these continents.

Question: Choose your answer.

In a lab investigation, students use Brand X batteries in a flashlight and Brand Y batteries in a radio. After two hours, the flashlight stops working, but the radio continues to work. As a result, the students conclude that Brand Y batteries last longer. Which statement about the conclusion of the investigation is most accurate?

OPTIONS:
- The conclusion is valid because they tested two different brands.
- The conclusion is invalid because the test had multiple variables.
- The conclusion is valid because they conducted the investigation in a lab.
- The conclusion is invalid because the real names of the batteries were hidden.
My Answer: The conclusion is invalid because the test had multiple variables.

Question: Choose your answer.

Which of these is an important safety rule to follow when using an electrical device?

OPTIONS:
- Wear an apron.
- Keep work area dry.
- Extinguish all flames.
- Wear protective gloves.
My Answer:
Keep work area dry.