请教pp2 test1-4的语法题:

JaneYang55

请教pp2 test1-4的语法题:

Cylamates were introduced in the early 1950's (as) alternative sweeteners (for) use (by individuals) who needed (reducing) their sugar intake for medical reasons.

答案是d错,可是 need+doing/to be done都是正确的用法啊,我认为是b错,应该为to use. 不知道是否正确,请大家给个答案.

onemore

need后加动词原形或to do
不象be+doing表现在进行

nlzhang

这个题我也很奇怪，need后可以加doing的

liusining

need 后加ing是表示被动吧
need +ing=need to be down