need doing 和need to be done 的区别单选题：it is a question that really_A____.A.don't need answering B.needn't to be answered为什么不可以选B 我在网上搜过 need doing 和need to be done是一样的 打错了 don‘t 是doesn't

need doing 和 need to be done 中,need 是实义动词,need 作为实义动词时不可以与 not 直接连用,再接动词时要接非谓语动词,即：作为实义动词 needn't 不存在,所以原句中B答案 needn't to be answered 要么是 needn't be answered,要么就是 doesn't need to be answered.
另外,如果句子后面用 by 短语附带“由某人去完成”时,通常用 need to be done.例如 ：
The door needs to be painted by a skilled worker. (这句不可用 need doing)