【题目】________ her grandma before, he didn’t know she was his grandma even if his mother had told him.
A．Not being seenB．Not having seen
C．Having not seenD．Not seeing
在线课程【答案】B
【解析】句意：因以前没见过她的奶奶，他不知道她是他奶奶即便他的母亲已经告诉过他了。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。