—Is Jack on duty today?

—It _________be him. It’s his turn tomorrow.

　 A. mustn’t　 B. won’t 　　　　　　　　　 C. can’t　 　　　　　　　　 D. needn’t

 I went to see him, ______him out.

   A. only finding       B. only find                C. only to find           D. find only

 All animals need air and_____.

   A. so plants do   B. so need plants    C. so do plants        D. plants are so

—Would you like to carry the box upstairs for me?

—Yes, _______.

　　 A. for pleasure　　 　　　　　　　　　　　　 B. my pleasure

　　　 C. with pleasure　　 　　　　　　　　　　　 D. I would

 __________, his plan is better than yours.

      A. With everything considered           B. Having considered everything 

      C. To consider everything                     D. Being considered everything

—You ought to have given them some advice.
—Yes，________, but who cared what I said?
　 A.I should　 B. I ought to have C. I did so D. I ought to

 We can _____Mrs. Smith for the night for free if he promises to give us a speech.

      A. put up      B. put aside                C. put out            D. put off

—Why does the Lake smell terrible?

—Because large quantities of water_________.

　 A. have polluted　　 　　　　　　　　　　　　 B. is being polluted

　 C. has been polluted　　　　　　　　　　　　D. have been polluted

 Over the past decades, sea ice _____ in the Arctic as a result of global warming.

      A. had decreased   B. decreased         C. has been decreasing D. is decreasing

 The teacher set so difficult an examination problem_____none of us worked out.

      A. that                       B. as            C. what                             D. which