21. We are not prepared to compromise _______ safety standards.

A. with        B. between       C. on          D. in

22.Generaly speaking, when _______ according to the directions, the medicine hads no side effect.

A. taking          B. taken         C. to take       D. to be taken

23. The visiting cousins expressed their satisfaction with their tour, ______ that they had enjoyed their stay her.

A. having added       B. to add       C. adding        D. added

24. Would you classify it _______ a hard drug or a soft drug?

A. into           B. by              C. as           D. apart

25. I am delighted to _______ your acquaintance, Mr. Baker.

   A. make          B. put           C. take                D. have

>  D. Who told you that?