不理解语法The molecules of gases move more freely than do those of liquids and solids.

题目

不理解语法The molecules of gases move more freely than do those of liquids and solids.
这句干吗要把 do 提前呢,如果这样说The molecules of gases move more freely than those of liquids and solids do.

答案

你的那样理解是可以的,但那样的话会使句子感觉不协调.
而在than do those of liquids and solids
中使用了倒装,使句子前后协调（前面是gases,后面是 liquids and solids,都是名词之间的比较）
在than 等引起的比较状语从句中,主谓可以倒装.