16.—I don't think waste water should be poured into the rivers or lakes.

   —______. It will cause much water pollution.

  A. Good luck           B. It’s my pleasure      

 C. I agree with you       D. The same to you

17. You must read the ______carefully before taking the medicine.

  A. news          B. pictures       C. numbers         D. instructions

18. Some of the books belong to me, while the rest are______.

  A. him and her     B. his and her    C. his and hers       D. him and hers

19.— Must I go to the shop with you, Mum?

  —Err…I can make it myself, Mike. You _____go with me.

  A. mustn’t         B. shouldn’t     C. wouldn’t         D. needn’t