Question: Choose your answer.

Some localized layers of rock contain the element iridium. Iridium is most often found in space objects such as meteoroids and asteroids. The discovery of these iridium-containing layers has been matched to which phenomena in Earth's history?

OPTIONS:
- tectonic plate separations
- mass species extinctions
- orbital path changes
- magnetic pole reversals
My Answer: mass species extinctions

Question: Choose your answer.

Fourth graders are planning a roller-skate race. Which surface would be the best for this race?

OPTIONS:
- gravel
- sand
- blacktop
- grass
My Answer: blacktop

Question: Choose your answer.

A large tree was cut down with a saw. What is the best way to estimate the age of this tree?

OPTIONS:
- measure the height of the tree
- measure the thickness of the bark
- count the number of rings in the trunk
- count the branches growing from the trunk
My Answer: count the number of rings in the trunk

Question: Choose your answer.

Which two factors determine the gravitational attraction between two objects?

OPTIONS:
- time and temperature
- shape and orbital speed
- color and hardness
- mass and distance apart
My Answer:
mass and distance apart