Question

There is ( ) A.key B. a set of key C a set of keys D. keys 选哪个？ 为什么

Answer 1

选C。
谓语动词的单复数根据set来定，前面的谓语动词是单数is，所以用 a set of（一串），一串钥匙肯定不止一片啊，所以后面用复数。
就像：There is a pair of shoes.
There are two pairs of shoes.

望采纳，不懂请追问》》》

追问

可是前面是is 后面是 keys 为什么可以

追答

看这个：There is a pair of shoes.
前面的is是根据set来定，而不是keys，就像这里的is是根据pair来定
我们可以说：There is a key. 有一片钥匙
There are two keys. 有两片钥匙
There is a set of keys. 有一串钥匙
There are two sets of keys. 有两串钥匙

不懂再追问》》》

Answer 2

选C
a set of keys 是一串钥匙的意思
前面是单数is所以后边也要是单数，可以填a key 、a set of keys
a set of 是词组
根据set来定，可以是a set 、 two sets等等，与后面的keys无关
set of后面都跟复数
比如说
There is a key.
There are two keys.
There is a set of keys.
There are two sets of keys.

Answer 3

答案C a set of keys
there is 单数，d选项排除
a选项应该是a key，没有冠词
a set of 固定搭配后跟复数
如果是sets of则应该是there are

追问

为什么前面是 is 后面是复数

追答

is是对a set of说的
keys是对a set of说的