Few people realized then __________ until two years later. A: how this mistake was serious B: how serious was his mistake C: what serious mistake it was D: how serious his mistake was

What problems are Asian countries facing according to the United Nations’ report A: Problems of water-shortages. B: Problems of flood, and the loss of farmland. C: Most problems of environment.

Sadly it is one of the most ______ problems facing this country. A: pressing B: promising C: proceeding D: preceding

—I wonder if I can get a raise in salary. —You have been paid enough, () do you want A: What else B: What more C: How much more D: How much

No one can be ______ calm when facing with a great danger. A: very B: so C: too D: enough