Question

_______ on earth do you suppose_______ this?

A．What; could do                         B．What; could have done

C．Who; do                              D．Who; could have done

Answer

D

【解析】

试题分析：句意：你究竟认为谁能做这件事？这里是特殊疑问句，do you suppose是插入语，插入语的语序必须是陈述语序，这里正好疑问词作主语，做事必须是某人来做所以排除AB，这里who做主语时，谓语动词应该用单数，故排除C。所以应选D。

考点：考查插入语的用法。