This is a more carefully
researched article than I have read this semester.这是《剑桥英语语法》书上的一个句子,请问这里可以在 than 后面加上 what 吗?This is a more carefully researched article than what I have read this semester.
If the air you’re breathing is clean-which it would
be if you’re away from the smog of cities-then the air is filled with
life-giving,energizing oxygen. which 引导的句子是什么成分?感觉像非限定定语从句,但是
it would be if ....句子应该是不缺成分。