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1、How do cats try to protect themselves when falling from great heights?
Cats never fail to fascinate human beings.
never fail to 双重否定意味肯定(运用双重否定结构加深句子肯定的语气)
-- If you ask for help in the polite way, you never fail to succeed.
-- If you receive requests like this, you'll never fail to accept.
双重否定结构：(起加深句子肯定的语气的作用)
1>否定词 fail to -- never fail to / can't fail to / don't fail to
2>否定的形容词之前加以否定
-- What he said is not unreasonable.(adj.不讲道理的, 不合理的)
-- It is quite common for us to make mistakes.=It is not uncommon for us
to make mistakes.
3> not without
-- You can't obtain English without working hard. Obtain(vt.获得, 得到)
-- He doesn't have any meal without meats.
4> no not -- There is no cat that doesn't like fish.
-- There is nothing that he can't do. 没有什么他不能做的。
-- There is no rule that has no exception. 没有无例外的法规。Exception(n.除
外, 例外)
2、They can be friendly and affectionate towards humans, but they lead
mysterious lives of their own as well.
as well 也, 又, 同样