30·You can make a complaint to the local government____ you are happy with the way things are.
| A．unless | B．if | C．once | D．As |
________ these experiments were successfully completed would we think of going into humans.
| A．If only | B．Only if | C．So that | D．Even if |
Currently, many American women are still faced with the ________ of choosing between work and family commitments.
| A．desperation | B．dilemma | C．confusion | D．Concern |
Tony ________ full marks, but he was so careless as to make a spelling mistake.
| A．could have gained | B．can have gained |
| C．must have gained | D．must gain |
Recently some Japanese have been trying to make conflicts with China, ________ effects we are greatly concerned.
| A．to whose | B．about whose | C．to which | D．about which |
Iraq has ________ too many wars since 1990, making his people ________ a lot.
| A．got through; pay | B．looked through; pain |
| C．gone through; suffer | D．passed through; damage |