are
由and连接的两个主语,如果表示同一个概念就用单数。两个概念就用复数
游泳和跳舞时两个事物,用复数
引用:
a) 由and连接两个名词或者代词作主语时
A and B分为以下四种情况:
i. A、B表示不同的人、物或者观念的时候,谓语动词要用复数形式
Li Ming and Zhang Hua are good students.
Both the parents and the children are here.
ii. A、B表示同一个人、物或者观念的时候,谓语动词要用单数形式
A journalist and author lives in the sixth flat.
The turner and fitter is under twenty-five.
iii. And连接几个单数主语,主语由each、 every、 no、 many等词修饰的时候,谓
语动词要用单数
Each boy and each girl is invited.
Every boy and girl is invited.
No boy and no girl is there now.
iv. A、B为两个不可分的东西时,谓语动词用单数
A law and rule about protecting environment has been drawn up.
Bread and butter is nutritious.