Do you know the flowers need watering every day?这句话正确吗

题目

Do you know the flowers need watering every day?这句话正确吗
我所写的是need be watered ,但是答案是need watering .所以,我想问一下,到底是我错了,还是答案错了.
要具体点啊.要肯定的真正答案.

答案

这题不难哦.
你句意理解的也正确.
但忘记了一点,
need to be done = need doing
你错了.
要改的话是:need to be watered