72-75 BACA
72.B 推理判断题，可用逻辑推断法来解。由原文最后一句In the same way the surface of the whole earth throws back enough of the sun’s light on to the face of the moon for us to be able to see the parts of it which would otherwise be dark.可以推出，月亮暗的一面之所以不完全暗是因为地球将一部分太阳光线反射到它上面。
73.A 语境词义判断题，可用语境词义推断法来解。认真阅读分析该词所在句可知，disc与full moon关系密切，可见其应指圆盘。
74.C 推理判断题，可用逻辑推断法来解。由第三节首句Yet the dark part of the moon’s surface is not completely black; usually it is just light enough for us to be able to see its shape, so that we speak of seeing “the old moon in the new moon’s arms”.可推出答案。
75.A 细节判断题，可用直接就题找文法来解。认真阅读分析原文可知，A内容符合原文事实，但B、C、D内容不符合原文事实。