than比较句中did的问题举个例子：A drink more than B did.这个did是咩啊?有咩用哩?

可以这么用,这个结构是A drink more than B drink的省略
比较状语从句中的省略
You can play the game just as wonderfully as I (do).
在以than和as引导的比较结构的状语从句中,省略某些与主句相同的成分或在特定上下文中有某些不言而喻的成分,可省掉整个as/than从句.
The pianos in the other shop will be cheaper.(than those in this shop),but (they are) not as good (as those in this shop).