Bits of glass were all over the floor.为什么glass是不可数名词还要加were呢?

问题描述:

Bits of glass were all over the floor.为什么glass是不可数名词还要加were呢?

因为bits是复数..
The kind of books is very good.
Large amounts of water are needed.
注意这两个句子的谓语动词.