问题
选择题
_______ to find the book from the library, she decided to turn to her professor for help.
A．Failed
B．To fail
C．Having failed
D．Being failed
答案
答案：C
题目分析：句意：从图书馆没有找到那本书，她决定向她的教授求助。现在分词作原因状语。上下文所
说的事情发生的时间显然有时间的先后。故要用现在分词的完成式="Because" she had failed to find the book
from the library…