—Is it that Jack often plays computer gamesmakes his parents worry about him ?—Yes I thi

问题补充：

—Is it that Jack often plays computer gamesmakes his parents worry about him ?

—Yes , I think so .

A. what

B. when

C. that

D. which

答案：

A. what

B. when

(答案→)C. that

D. which

解析：考察强调句，强调句的特点是去掉it is that之后，句子完整，不缺少成分，即，that jack often plays computer gamesmakes his parents worry about him.