It was the boy said he almost never did any exercise in the school the mother began to worry about his health.
A. what; that
B. that; how
C. when; that
D. that; that
网友回答
A. what; that
B. that; how
(答案→)C. when; that
D. that; that
解析：本句强调状语，且这一时间状语是由when来引导的从句充当的。