Question

The reason__________ their failure you know is__________ they didn't get fully prepared for the experiment．

A．why, that

B．that, why

C．for, that

D．why, because

Answer 1

C

试题分析:重点在句子成分分析，is 为主句谓语。You know 为定从  that 引导表语从句。
for 表“对于”。句意：对于你知道的他们失败的原因是他们没有为实验做充足的准备。故选C
点评：本题较难，乍一看不知如何下手，所以认真分清句子成分是解题的关键。可利用排除法解题。