Question

【题目】________her grandma before, he didn’t know she was his grandma even if his mother had told him.

A．Not being seen B．Not having seen

C．Having not seen D．Not seeing

Answer 1

【答案】B

【解析】否定词not要放在非谓语动词的前面，排除C选项，本句的主语是he，与see之间是主动关系，排除A，由于see 与didn’t know两个动作有先后，故选B。