there be 句型+单复同形的名词,be动词单复数
例如：
（1）山上面有绵羊.
There is a sheep on the hill.（一只）
There are some sheep on the hill.(多只）
（2）河里有鱼.
There is a fish in the river.
There are some fish in the river.
根据be后面的名词的意义确定be的单复数形式.