When if he hadany idea what the novel was about Jack kept silent. He have read it very ca

问题补充：

When if he hadany idea what the novel was about, Jack kept silent. He have read it very carefully.

A. asking; needn

B. asking; shouldn

C. asked; can’t

D. asked; mustn’t

答案：

A. asking; needn

B. asking; shouldn

(答案→)C. asked; can’t

D. asked; mustn’t

解析：原句意思是当被问及他认为这部小说写了些什么，杰克就保持沉默。谓语动词ask和主语Jack是被动关系。needn have done 表示过去做了不必做的事情shouldn’t have done 本不该做某事can’t have done 表示对过去某种情况的怀疑或不确定mustn’t have done禁止做，故选C，最符合题意。