Tom has been to the US before.(改为否定句)
Tom to the US before.
Could you please speak more (slow)? I can't follow you.
We all take (骄傲) in the great achievements of our country.
You must check your papers (认真地) in the exams.
As we all know, hard work is the key to (成功).
After a long walk, he felt (饥饿的) and thirsty.