高中英语表语从句练习Ithinkitis_____youaredoingtoomuch.AbecauseofBbecauseCbecausethatDdueto我知道这一题选B.可是C和D怎么错了?becausethat后加句

　　高中英语表语从句练习

　　Ithinkitis_____youaredoingtoomuch.

　　AbecauseofBbecauseCbecausethatDdueto

　　我知道这一题选B.可是C和D怎么错了?becausethat后加句子啊,dueto为什么也不对呢?BCD区别是什么啊,速度,谢谢