1、(2012·重庆卷·34). Evdence has been found through years of study______ children’s early sleeping problem likely to continue when they grow up.
A. why B. how C. whether D. that
【解析】选D名词性从句,分析句子结构可知,空白处后面为句子主语“Evidence”的同位语从句,在这一从句中,句意完整,不缺少成分,应该使用“that”作为引导词。因此,正确答案为D选项。考查同位语从句。evidence 后面的部分是其内容,即同位语从句,从句中不缺少成分,应该that作为引导词,故正确答案为D选项。