mary ( ) a bag( ) school 第一个,need,needs 第二个,at,for哪个

mary ( ) a bag( ) school 第一个,need,needs 第二个,at,for哪个 Lucy _____ a bag for school.A.need B.needs Do you need a bag for sports or school? He left the house with a bag in the left hand.的第一个和第二个left的词 第二题第一个字哪个对? 请问 two pieces of candy a bag of candies 第一个糖没加复数 第二个 怎么就加了复数 英语题目（说明理由）第一题We need time__________(exercise) at school第二题Do ( )6.Mary --- a notebook and a pen A.need B.needs C.to need She needs help ____ math A.to B.for C.at D.with选哪个, A is substituted for B,A substitute for B.为什么第一个句子药用被动,还和第二个 改错：You need buy a new school bag. 第二个空 A.on B.for C. at D.in