Evidence has been found through years of study children’s early sleeping problems are likely to continue when they grow up.
A. why
B. how
C. that
D. whether
网友回答
A. why
B. how
(答案→)C. that
D. whether
解析：通过分析句子结构，可知这个句子中包含一个同位语从句，且引导词在同位语从句中不作任何成分，且没有实际意义，故用that。