Expressions
(1)当be后所接的名词是单数可数名词或不可数名词时，be 应该取单数is；当其后所接的名词是复数的可数名词时，be用复数are.
There‘s a man at the door. 门口有个人。
There be 是英语中常用句型， 表示“有”
eg: There is some apple juice in the bottle. There are some strangers in the street.
