China's reform and opening has been going on for ________ is like about 30 years now and it's really quite remarkable.
| A．that | B．which | C．what | D．it |
It ____ Mike and Mary who helped the old man several days ago.
| A．was | B．were | C．are | D．had been |
____ is no difference between A and B.
A. It B. Where C. There D. What
Was it in the place ____ the last emperor died?
| A．where | B．that | C．which | D．in which |
It was simply for that reason ____ I wouldn’t tell him the truth.
| A．why | B．which | C．so | D．that |
It’s the third time ____ I have been here.
| A．that | B．when | C．after | D．who |