(2013·新课标Ⅱ，10)It was only after he had read the papers Mr.Gross realized the task before him was extremely difficult to plete.
A. when
B. that
C. which
D. what
网友回答
A. when
(答案→)B. that
C. which
D. what
解析：考查强调句。题干可还原为：Mr.Gross realized the task before him was extremely difficult to plete only after he had read the papers，即可判断为强调句，因此填that。