The research is so designed that once _______ nothing can be done to change it.
| A．begins | B．having begun | C．beginning | D．begun |
He insisted that he _____ the best, so he insisted that he _____ the work all by himself.
| A．was; do | B．be; do | C．be; did | D．had been; had done |
—_________ I have a look at your new MP3?
Certainly. Here you are.
| A．Must | B． Need | C．May | D．Would |
The boy is lying on the ground, _________ at the aeroplane in the sky.
| A．looked | B． to look | C．look | D．looking |
. — What about going to the theatre this evening?
— _________ .
| A．Help yourself | B．That’s all right | C．Good idea | D．Not at all |
. We ______________ last night, but we went to the concert instead.
| A．must have studied | B．might study |
| C．should have studied | D．would study |