4.When he was there, he ______ have been to that coffee shop at the corner after work every day.

选a，用将来完成时，表示一种推测的语气

A

would have been 就会

he would have been to that coffee shop at the corner after work every day.
他每天就会在下班后去那个坐落在角落里的咖啡店。

D才是正确答案

A would have been表示虚拟语气，
比如:Had such calamities occurred in old China, the damage would have been incalculable.
这样的灾害要是发生在旧中国的话，损失将是无法估计的。（实际上并没有发生在旧中国）

B should have been表示本该做某事而没做成。
比如：Look at the time! We should have been at the theatre ten minutes ago.
瞧都什麽时候了! 十分钟前我们就该到戏院了.

C had better不符合逻辑，“最好...”
比如： You had better have another think.
你最好再想一想。

只有D表示对过去可能发生的事进行的猜测。除非有上下文背景的情况下，证明这句是虚拟句，才能选A。

A. would

D.

A