31.   He called for tougher restrictions on contributions to political parties.

32.   He has done so by manipulating contributions to certain government retirement plans.

33.   He has made a major contribution to public understanding of science through his books, lectures and broadcasts and through the Exploratory.

34.   He is unable to separate his contribution to what should be a well-informed debate from a satellite television knockabout.

35.   He made a valuable contribution to our work.

36.   He strongly implied that part of the plan involved funneling campaign contributions to members of Congress, state officials and presidential candidates.

37.   He then made a major contribution to the development of the internal combustion engine, originating the use of aluminium for pistons.

38.   Her contribution to horticulture was recognized when a new rose was named after her.

39.   Her only contribution to the phone conversation was an occasional monosyllable.

40.   His book is a major contribution to that end.