GWD16-30

Q30:

According to public health officials, in 1998 Massachusetts became the first state in which more babies were born to women over the age of thirty than under it.

1. than
2. than born
3. than they were
4. than there had been
5. than had been born

每次一碰到than比较结构的题，就很害怕比较对象的问题呀，还有than后面总是省略， 但是省略的什么更是弄不明白啊……比如这道题，可以用排除法得A，但是than后面省略了什么呢？实在想不明白啊，大家给我讲讲吧～～万分感谢～～

比较结构比较的如果不是主谓结构，而且比较对象的主谓一致时，主谓结构可以省略，但保留介词结构，如此题：more babies were born to women over the age of thirty than (babies were born to women) under it. 括号内的内容可以全部省略。