When Marx was in London he read at the library for hours.A. wouldB. mightC. couldD. shou

问题补充：

When Marx was in London, he read at the library for hours.

A. would

B. might

C. could

D. should

答案：

(答案→)A. would

B. might

C. could

D. should

解析：考察情态动词用法。情态动词would表示过去常常做某事，而且现在还可能在做。Might表示也许，用于肯定句指，是一种可能性很小的推测。Could能够；should应该，竟然；句意：当马克思在伦敦的时候，他经常在图书馆里阅读好几个小时。故A正确。