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?
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?
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?
My Answer: count the number of rings in the trunk

Question: Choose your answer.

Which two factors determine the gravitational attraction between two objects?
My Answer:
mass and distance apart