分类：教育/科学-外语学习
问题：_________theproblemathirdtime,he? 
_________ the blem a third time,he finally found the way to work it out.A. Read B. Reading C. While reading D. When you read 
回答：选B.
用动词的ING形式做伴随状语,注意,这里的动词READ的发出者就是这句话的主语HE.
其他的都不正确,A句意不对,而且成了一句话里面有两个谓语动词.
C里的WHILE应该加一句完整的话,如WHILE HE WAS READING.... 
D句意不正确.