The population of China is 1.3 billion.

题目

The population of China is 1.3 billion.
Three fifths of the population in our school are wemen teachers.
同样是population作主语,为什么前一句中用is,后一句中用are?

答案

这个主要通过看be动词后面的成份来判断其主语是单数还是复数.
The population of China is 1.3 billion.be动词is后面是一个数字,所以很明显用第三人称单数形式；
Three fifths of the population in our school are women teachers.be动词后面是women teachers,很显然是复数,那么主语three fifths of the population也就倍当作是复数了.
希望对你有所帮助.