英语题，请说明详细语法和理由

Question

1.he thought that computer would never be __ most people.
A used by B used for C useful by
为什么不能选C呢
2 If my father __ here now,he __ tell me what to do.
A were,would B were ,will C was,will D is,would
3 he is a __ man.
A short-neck B short -necked C short necked
为什么不能选B?
第三题正确答案是B，为什么不能选c呢

Answer 1

1.he thought that computer would never be __ most people.
A used by B used for C useful by
选A ，be used by sb （被。。使用）；be useful for sb（对。。有用），考搭配问题

2 If my father __ here now,he __ tell me what to do.
A were,would B were ,will C was,will D is,would
选A ，考虚拟语气的用法；
对现在的虚拟：if从句的谓语动词用were、did的形式，主句用would、could、might+do的形式

3 he is a __ man.
A short-neck B short -necked C short necked
答案为B ；形容词+名词ed 形式表示 怎么样的。。。。
=
he is a man with short neck

追问

恩，前两题都懂了，，O(∩_∩)O谢谢啦。。那第三题为什么不能选c呢？

追答

这个语法不是我规定的，所以我只能把我的理解跟你讲下，
形容词+名词+ed 才是一个正确的结构，这个结构用作形容词用；大概就是这样的，因为可能你现在见的东西还不够多，所以会对一些新出现的结构表示疑惑，这个很正常，这才是学习慢慢增长知识过程之处嘛，祝，学习进步

Answer 2

根据句子意思，电脑室被人们用，所以use(用)要加d 才构成被动语态 选A
2.D
3.因为加ed 才构成形容词