He was unhappy when he sold his guitar.After all，he ________it for a very long time.
| A．has had | B．had had |
| C．has | D．had |
—How long do you think it will be___ the Stock Market returns to normal?
—At least one year, I guess.
| A．before | B．when | C．until | D．that |
His promise ___ he would marry her when he came back turned out to be a lie, ___ left the girl heart-broken.
| A．which; what | B．that; which | C．what; which | D．which ; that |
If we ___________some measures, we might have prevented the environmental pollution．
| A．take | B．had taken | C．took | D．have taken |
Many Chinese universities provide scholarships for students _____financial aid．
| A．in favor of | B．in honor of | C．in face of | D．in need of |
Scientists are convinced _____the positive effect of laughter _____physical and mental health．
| A．of ;on | B．by; in | C．of ; at | D．on ;at |