太阳系的天体大都有坚固的外壳。除非一个天体的内核有足够热能造成火山爆发，否则，它的外壳几百万年都不会有大变化。任何一个有坚固外壳，并且这一外壳几百万年都未有大变化的天体，其表面都会布满陨石坑，就像地球的卫星月亮那样。太阳系中有些古老的天体，像木星的卫星木卫二，有被冰覆盖的坚固外壳但上面很少有陨石坑。
如果上述断定为真，可以推出以下哪项一定为真?

A 20％ B 25％ C 22％ D 15％ E 12％

A 2015 B 2016 C 2017 D 2018 E 2019

A 24 B 32 C 35 D 40 E 50

A <img width="27" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184314_4462.jpg" /> B <img width="27" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184315_8768.jpg" /> C <img width="27" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184316_9930.jpg" /> D 4 E 5

A 4 B 5 C 6 D 7 E 8

A 2 B <img src="https://www.beizhujiaoyu.com/uploads/202208/165235461343591.png" width="38" height="17" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/165235461813401.png" width="20" height="17" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/165235462397731.png" width="36" height="17" /> E <img src="https://www.beizhujiaoyu.com/uploads/202208/165235462711331.png" width="71" height="18" />

A <img width="27" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184331_4462.jpg" /> B <img width="26" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184334_3681.jpg" /> C <img width="40" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184334_5243.jpg" /> D <img width="27" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184336_4930.jpg" /> E <img width="40" height="58" src="https://www.beizhujiaoyu.com/uploads/202208/20220217184336_6493.jpg" />

A 2 B 2．4 C 3 D 3．6 E 4．2

A 80 B 120 C 160 D 200 E 240

A -6 B -9 C 6 D 9 E 0