问题补充:
—The classroom is clean it was yesterday.
— Sorry, I forget to clean it.
A. as; as
B. so; as
C. not so; as
D. more; than
答案:
A. as; as
B. so; as
(答案→)C. not so; as
D. more; than
解析:as; as 和……一样;so; as和……一样,用于否定句;not so; as不如……;more; than比……更。句意:教室不如昨天那样干净。——抱歉,我忘了打扫。结合语境可知选C。