我还有个问题是为什么要用which不用that

我还有个问题是为什么要用which不用that I turned to look at the children,but there weren't any in sight.第一个问题是为什么用there?而不用they?第二个问题是为什么要加上any?没有any个人感觉反而好···他是固定搭配么? it was because he was ill that he didn't come 为什么要用that而不用which that 的用法Don’t talk about such things of which you are not sure.为什么不用that用 which 我们有个同学每天装上自来水,用太阳晒一晒喝……我跟他说喝开水,他还是喝自来水问题是我想知道他为什么要喝自来水,还有为什么要晒一晒再喝?杀毒么? doesn't want to know that which she is eager to know.这里为什么用which 而不用wha而不用what? 请大家帮我解释下ones的用法I wasn't sure which ones would be most useful or important.这里为什么要用ones 而不用one呢什么时候用ones啊 英语翻译为什么不用which I decide which one to buy.为什么要用which one to buy?而不用which to buy?谢谢.I decide which one to buy. 为什么要用which one to buy? 而不用which to buy?谢谢. I will tell her __ he told me yesterday.为什么不用all which which that?而要用all which? 1.He pretended (not to) know me.这里为什么要用pretended to do sth.而不用pretended doing sth.2.We heard (her singing) in the room yesterday.这里的sing为什么要加ing?第二个问题我弄明白了，第一个问题是为什么？ 请问应急格栅灯用LED灯管怎么接呀?以前用的是普通荧光灯管要用镇流器,现在换成LED不用镇流器了.是双管格栅灯,里面带电池,逆变器.急.各位大哥们,我知道怎么接,问题是现在还有个电池逆变 He didn't know which office room_____.为什么用to send it to,而不用to have it sent to I hate people_don't help others when they are in the trouble.划线处为什么用which,不用who? Which do you prefer ,coffee or tee?( )will do.I don't really mind.为什么用Either不用Both. The fact ()he didn't see Lao Li yesterday is true.为什么用that而不用which as a new graduate,he doesn;t know it takes to start a business here.为什么用what不用which? which and of whichstrong white teeth,of which some are filled with gold;这个句子为什么要用of which,不用which