小窍门:去掉引导词可以和前面名词画等号的是同位语从句去掉引导词后缺少名词，成分不全的是定语从句。比如:He told us the fact that he made his sister cry.(去掉that可画等号)同位语从句He told us the fact that he used to hide.(去掉that句子缺少宾语)定语从句
