1) but表示转折,while表示对比。
Some people love cats, while others hate them.
例题:
-Would you like to come to dinner tonight?
-I'd like to, _____ I'm too busy.
A. and B. so C. as D. but
答案:D。
解析:but与前面形成转折,符合语意。而表并列的and, 结果的so,原因的as都不符合句意。
2) not…but… 意思为"不是……而是……",not 和but 后面的用词要遵循一致原则。
例句:
They were not the bones of an animal, but (the bones) of a human being.