Q18: GWD-4-4请教

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.

A.      as

B.       than

C.      that

D.      of what

E.       at which
        

答案是C:THAT.我不知道为啥选THAT

请问是不是要charge the price for sth.

谢谢大家了

选D

of what...

three times of what the drug's maker charges...

我认为of what是正确的

3 times of sth， what是maker charge的price，引导名词性从句。

所以就是A new hair-growing drug is being sold for three times the price of（ the price）

一个价格是另一个价格的三倍，逻辑意思很正确