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
答案:C
题目分析:句意为:孩子早期的睡眠问题在他们长大的时候似乎会持续的证据经过几年的研究已经被发现了。所引导的从句是evidence的同位语句从句,解释了evidence的内容,且后面的从句不缺少成份,无疑问的意思,故答案应为C。