When I entered the room, I found Mary ______ at the desk ______ her homework.

He wants to do nothing but _______ his homework.

         seems to be one of the main reasons for many people        in today’s world.

The couple tried every effort to      the judges, who tried the cases, of their innocence (清白) only    in the contrary.

— ______ him off tomorrow, or you will regret it.
— I will.

When the young man found himself ____ in the land with so many beautiful flowers ,he felt delighted .

The letter he had been looking forward to ____ at last .

The professor explained this theory so clearly that this phenomenon was easy enough ________.

He has devoted himself __ mankind.
to benefit       B. benefiting    C. to benefiting    D. benefited

—I’ m sorry, but I didn’t mean__________ out your secret.
—But you know, letting out one’s secret means________ one’ s feelings.