问题补充：
I can’t buy that one.
A. as good a book as
B. as a good book as
C. such good book
D. so good book as
答案：
(答案→)A. as good a book as
B. as a good book as
C. such good book
D. so good book as
解析：
考点分析：as..as 同级比较。 在as 。。as结构 中，第一注意用形容词或或者副词的原级， 第二注意第一个as相当于so ，所以as +adj +a/an +名词的结构。
