We usually think of pollution _____ a harmful waste substance.A、forB、asC、byD、about

______ we can get rid of pollution is still a big problem.A．WhetherB．IfC．thatD．what

Usually he managed to find plenty of work to ______ him over hard times. I think it is a g

We can infer from the end of the passage that______.A．a poet is usually insightful of and

We must not think of this writer as a radical socialist politician, ______ a leader of a r

We can infer from the passage that ______.A．men usually tend to restrain the expression of

We find that expected noises are usually more______ than unexpected ones of the like magni