狒狒135_16,拜托大家来看下~~

The axis of Earth’s daily rotation is tilted with respect to the plane of its orbit at an angle of roughly 23 degrees. That angle can be kept fairly stable only by the gravitational influence of Earth’s large, nearby Moon. Without such a stable and moderate axis tilt, a planet’s climate is too extreme and unstable to support life. Mars, for example, has only very small moons, tilts at wildly fluctuating angles, and cannot support life.

If the statements above are true, which one of the following must also be true on the basis of them?

A.       If Mars had a sufficiently large nearby moon, Mars would be able to support life.

B.       If Earth’s Moon were to leave Earth’s orbit, Earth’s climate would be unable to support life.

C.       Any planet with a stable, moderate axis tilt can support life.

D.       Gravitational influences other than moons have little or no effect on the magnitude of the tilt angle of either Earth’s or Mars’s axis.

E.        No planet that has more than one moon can support life.

答案是B,但是A为什么不对呢?我觉得A和B是一个意思啊.

分析一下：如果AXIS有倾斜角度是23度，这个角度真好能够满足地球的引力需要（kept fairly stable only ）记住only。

推理：没有AXIS倾斜角度， 那么行星天气恶化，不足以生命生存。

B中
            If Earth’s Moon were to leave Earth’s orbit 代表就是：没有AXIS倾斜角度，月亮就离开地球轨道。 Earth’s climate would be unable to support life地球不支持生命。就是原推理

A
                If Mars had a sufficiently large nearby moon：火星有足有大的月亮靠近，并不能说明火星也保持AXIS角度平衡。原题目中支持条件是AXIS有倾斜角度，而不是一个大月亮阿