7. What is a meteorite? It is a
A. dim meteor
B. bright meteor
C. meteoroid that lights up
D. remains of meteoroids that hit the Earth

8. What is a comet? It is a/an
A. rock from Mars
B. class of smaller inner solar system bodies that orbit around the sun
C. icy ball of rock that displays a coma, a fuzzy temporary atmosphere, or a tail
when it travels close to the sun
D. natural object from small to huge that originates in space and survives the
impact on the earth's surface

9. What composes silicate?
A. silicon, oxygen, and at least one metal
B. silicon, carbon, and at least one metal
C. silicon, methane and a rock
D. iron, nickel, and argon

10. Why do scientists study comets?
A. They are valuable minerals.
B. They could provide Earth with rocks.
C. They can help make the Earth a habitable planet.
D. They provide information how the Earth obtained liquid water.

11. Why would global temperature of the Earth drop when struck by a massive
asteroid?
A. The resulting cloud would block out sunlight.
B. The low temperature of asteroid would chill the oceans.
C. The impact would move the Earth farther from the Sun.
D. The ice in the asteroid would increase the Earth's reflective power.

12.When objects strike a surface of a planet, they leave a deep impression on the
surface called
A. canyon
B. crater
C. plateau
D. pothole

13. Meteoroids are formed when asteroids collided and crushed into pieces. Based
on this statement, where did the meteoroids originate?
A. Asteroid Belt
B. Mars
C. Moon
D. Sun​