He used the small room ___ a lab.

—I’m going to cut the big trees down..—What________?

We should consider what use can be made ______ such a material(材料).

The accident that happened at an oilfield____ the southeast coast of the U．S．A has caused great damage to the environment.

Check carrots，potatoes, onions and any other vegetables_____   and immediately use or throw away any which show signs of rotting.