请教：OG 11版橙皮书语法第4题，新题。

刚才看了该题的讨论汇总。没有解答我自己的疑问，所以另开新贴请教。

答案选项：

C）double what it was in 1977

D）double the figure for 1977

正确答案是D。OG解释选项C为awkard,wordy和unclear。

三个疑问：

1，D中为什么要用介词for？of 或者别的不行吗？我就是没想明白为什么要用for。

2，double此处什么词性？很多人说是形容词，但我觉得是否动词？因为double之后跟着the figure这个名词。是否可理解为这是一个定语从句，which doubles the figure for 1977。但我没想明白，也不确定。

3，选项C为什么是awkard,wordy和unclear？我觉得它表达得很清楚啊。是否因为it所以说它unclear。但它紧跟在20736female ministers,almost 9 percent of the nation's clergy之后，我觉得表达得很清楚it是指代前面所说的数字。

请教！

1. you have to copy the whole sentence if you really want to know the meaning of the prep.

2. of course, vt.

3. awkward means 'double what' is never heard.

   wordy suggests a 'figure' is much more concise than 'what it is'

   unclear indicates that 'what it is' can mean anything, not necessarily associating with a figure