[讨论]大家快来帮帮我这道题!!(几道真题）

1。(A)Over the course of  the 18 century,the average output of ironwork tripled as a result of several improvement in blowing machinery and because coal replaced charcoal as the fuel used in the smelting of iron core.

(c).With  charcoal's being replaced by coal as the fuel used in the smelting of iron core and several improvement in blowing machinery, the average output of iron tripled over the 18 century.

2.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.  that  

c.  than

d. of what

  e.at which

这两道题 是以前考试中遇到的真题

请那位高人指点

关于第二道题，我同时问过三个老美，她们的答案都不一样，后来我跟她们说答案是d,其中一个mm恍然大悟，就跟我这么解释的：three times  of what  the drug's maker charges ...，是英语里面的一种用法，中间的 , per milligram 可以忽略掉。what 可以用来指代 the price ...