More than three quarters of the population are Chinese.句中be动词为什么用了复数?

问题描述:

More than three quarters of the population are Chinese.句中be动词为什么用了复数?
不可数名词be动词只能用单数,难道population有什么特殊的用法吗?请赐教?

该词是一个集合名词,做整个集体讲时动词用单数,但若是讲分开的个体时就用动词的复数形式