A series of attempts______made, he came to a successful solution of the problem.

游客2025-03-07 41

问题 A series of attempts______made, he came to a successful solution of the problem.

选项 A、to be
B、had been
C、were
D、having been

答案 D

解析这是一道语法题。考点是动词过去完成时被动语态的用法。

转载请注明原文地址:https://www.tihaiku.com/zcyy/3986509.html

相关试题推荐

随机试题

最新回复(0)

Theshortageofenergyisgettingworse.It______animmediatesolution.A、calls