I have heard a lot of good things about you __________ I came back from abroad.
| A．since | B．until |
| C．before | D．when |
_____in the mountains for a week , the two students were finally saved by the local police．
| A．Having lost | B．Lost | C．Being lost | D．Losing |
When he heard the news , he stared at me ________．
| A．in amazement | B．in disguise | C．in brief | D．in particular |
The head of the company promised to deal with matters of this sort _____he returned to his office．
| A．until | B．while | C．by the time | D．the moment |
The disk ,digitally ______in the studio, sounded fantastic at the party that night．
| A．recorded | B．recording | C．to be recorded | D．having recorded |
Scientists are convinced _____the positive effect of laughter _____physical and mental health．
| A．of ;at | B．by; in | C．of ; on | D．on ;at |