问题补充:
-----The classroom is clean it was yesterday.
------Sorry, I forgot to clean it.
A. as, as
B. so, as
C. not as, as
D. more, than
答案:
A. as, as
B. so, as
(答案→)C. not as, as
D. more, than
解析:句意:----教室没有和昨天一样干净。----对不起,我忘记打扫了。not so/as…as…和……不一样……clean的比较级是cleaner,根据题意,故选C