________hergrandmabefore,hedidn’tknowshewashisgrandmaev...
问题详情：
________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 |
【回答】
B
知识点：动词时态与语态
题型：选择题
