1、John said he'd been working in the office for an hour,_was true.

问题描述:

1、John said he'd been working in the office for an hour,_was true.
A、he B、this C、which D、who
2、_in thought,he sat still in the sofa.
A、losing B、having lost C、lost D、to lose
3、The research is so designed that once_nothing can be done to change it.
A、begins B、having began C、beginning D、begun
希望能得到比较详细的答案
题一中B为什么不行?
题二中B为什么不行?
题三中B为什么不行?

CCA由于是逗号,是一句话不是两句.只能填which不能真this.故选Clost指He was lost in thought.简化为lost in thought故选Conce 后面承前省了主语.省掉了The research ...应为once (the research) begins 故选A...