Question

选择题 We ___ the manager ,but no one ____ his telephone number.

A.could have called,knew B.could have called,had known C.could call,had known D.could call,knew

Answer 1

A.could
have
called,knew
我们本来可以打电话给经理的，但是那时候谁都没有他的电话号码。
call是个短暂性动词，know
是个表状态的动词。
前边应该是
过去完成时
，后边是过去式。

Answer 2

你好！
选A
could
have
done
表示本应该做，却没做
know
是短暂性动词，不能用完成时！
如果对你有帮助，望采纳。