GWD语法。。。就是不明白为什么要用That C选项

Sophin

Q18: GWD-4-4

A new hair-growing drug is being sold for three times the price, per milligram, as the drug’s maker charges for another product with the same active ingredient.

1. as
   
   
2. than
   
   
3. that
   
   
4. of what
   
   
5. at which
   
   

lusun23

read the Grammar Note...