下面这句话为什么用to use?而不用usingIt is no doubtthat it is a tradition to use chop

下面这句话为什么用to use?而不用usingIt is no doubtthat it is a tradition to use chop 为什么这句不用benzine而用petrol?——u should use [retrol] to get those stains off Do you have to pay to use these computers? 为什么借此不用for而用PAY TO take exercise often,child这句话为什么用take 而不用 taking或者to take Did you use to afraid of the dark?为什么要用did为什么要用did，而不用are Do you know the key to the question?这句话里key后面为什么用to而不用of? 英语The important thing is to keep the earth clean.这句话为什么用to keep,而不用keeping? 什么时候用where而不用that?例如 Last summer he went to the city______he had visited twice.这句话横线上为什么只能填that,而不用where？ it doesn't seem very possyble to move a mountain.这句话中为什么用a而不用the? Did you use to be afraid of the dark?为什么要用Did而不用Were.afraid不是形容词吗？为什么be afraid当做动词 She found herself worked to death.这句话怎么理解啊 ,为什么用worked而不用work.这句话是出自一本英文 伏安特性曲线为什么不用U I线,而用I u线呢 The parents will use ____they have to send their son to technical school 为什么只能用what ,而不用all our question were about use of the Internet 为什么这个地方用use而不用using是our questions were about use of the internet 为什么这个地方用use而不用using How _____(容易)you will find it to use this mobile phone if you read its instructions carefully!为什么要用easy而不用easily every time you take a bath you can easily use 120 to 160 litres of water.为什么用easily而不用easy快回答 I wish him to go there with me (wish的问题I wish him to go there with me 这句话中为什么用wish而不用hope? 在这里为什么用those而不用them?As most people know,the government makes regular use of the media to educate （them） who use the beaches.答案说应该把them改成those 为什么