__ is surprising to us is that Tom, for _______English was once boring, can speak English fluently as though he were a nativespeaker.

. He put it firmly that in no case _______ give in to others on such matters.

Finally I turned the key in the lock and_____ the door open, with Dad still complaining (抱怨) about a hurting kneeor something.[ ]

You can never be_____careful ; the road is icy and slippery.

The Americaneconomy is still in trouble，________the Chinese economy is beginning to pick up