( ) 28. Things fall to the ground _______ go up into the air because of gravity.
| A．instead of | B．than | C．rather than | D．in place of |
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 |
Could you give me a hand? It seems that my strength has _________.
| A．used up | B．been given out | C．run out | D．been run out |
Unfortunately, ____ stone hit him on ______ head and he got injured.
| A．the; a | B．a; 不填 | C．a; the | D．the ; the |