单选题：—Can I pay the bill by check?—Sorry，sir．But it's the mana..

It is obvious that people hold different opinions about _____ voluntary services should be financially rewarded.A. that B. what C. if D. whether

Oh, I'm not feeling well in the stomach. I ________ so much fried chicken just now.A．shouldn't eatB．mustn't have eatenC．mustn't eatD．shouldn't have eaten

A hot balloon blew up in Egypt. There ________ something wrong with the quality of it.A．may have beenB．must beC．need have beenD．might be

—Is it necessary to look up every new word when I come across it in reading?—No. You ________， because you are likely to guess the meaning from the context.A．can'tB．mustn't C．don't have to D．ought not to

The boys are still playing basketball happily on the court _____ it is raining heavily.A. in case B. even though C. as if D. as long as