Bob looked out of the window.There___he had never seen before.
问题描述：
Bob looked out of the window.There___he had never seen before.
A.a boy did stand
B.a boy stood
C.did a boy stand
D.stood a boy
求详解
答
D,there放在前面后面要倒装,然后he had never seen before是用来修饰a boy的,即那儿站着一个他从没看过的男孩.