单项选择题

What's Kirkwood Gap

A．A belt located between Mars and Jupiter.
B．Different regions in the asteroid belt.
C．The mysterious gap between different regions of the asteroid belt.
D．Ceres, a ball about 637 miles in diameter.

<上一题目录下一题>

热门试题

单项选择题

According to the second theory, why did the solar system clear everywhere except in the asteroid belt

A．The asteroid belt was too far away from the sun.
B．In the asteroid belt, the gravity of Jupiter was strong enough to balance the opposing pull of the sun.
C．The solar system prevented fragments from accreting into their own planets.
D．The asteroids are leftovers from the days of creation.