这题用白勇的语法全解怎么解释不通啊?

Retailers reported moderate gains in their November sales, as much because of their sales of a year earlier being so bad as that shoppers were getting a head start on buying their holiday gifts.

1. of their sales of a year earlier being so bad as that
2. of their sales a year earlier having been as bad as because
3. of their sales a year earlier being as bad as because
4. their sales a year earlier had been so bad as because
5. their sales of a year earlier were as bad as that

  这题选D,但是 SO .....AS .....不是只能用在否定句中吗(根据白勇语法全解)

an obvious parallel of comparision. you must understand the whole sentence and use the method "three words before and behind underlined words"

“as much because of their sales of a year earlier being so bad as that shoppers were getting a head start on buying their holiday gifts”

这个句子不是so...as...结构的，而是as much ....as.....结构的。

明白了这一点之后，我们所要做的就是找到两边的平行结构了，两个平行的短句都是指原因的。

谢谢了！偶明白了！