Every possible means to prevent the air pollution, but the sky is not still clear.
| A．is used | B．are used | C．has been used | D．have been used |
The two things are the same in outward form but different________.
| A．in addition | B．in brief |
| C．in common | D．in essence |
We’d better discuss everything ________ before we work out the plan.
| A．in detail | B．in general |
| C．on purpose | D．on time |
Those overseas students volunteer 10 hours each week in Paris ________ free food and accommodation.
| A．in search of | B．in contact with |
| C．in case of | D．in exchange for |
—When did it begin to snow?
—It started________the night.
| A．during | B．by | C．from | D．at |
Never put the medicine________the reach of your little child in case he takes it by mistake.
| A．beyond | B．within |
| C．across | D．from |