谢谢小美人鱼!再问一句中 it 指代?

casamila

In 1990’s, there are more babies were born by women over thirty years old than under it.

A than under it.
B than were they under it.
C than had been under it
D than were the babies.
E than those were under it.

为什么选 A ? 如果把 than 后省略部份补齐, 应该是什么?

深海的小美人鱼

it指代30 years old.补全了是
In 1990’s, there are more babies were born by women over thirty years old than those by women under 30years old

casamila

疑问---
IT 不是只能指代前面出现过的单数可数名词吗,这里指代 30 years old不是违背了这一原则吗?

深海的小美人鱼

30 years old在这里是一个标准，不是指时间量，所以用单数。