例：We often visit the museum last year.      答案：visit改为visited

    Last month, my English teacher asks me to take a part in an English speaking competition. But I doubt that I have the ability to win. It is known to all my classmates that I can always speak English as good as a native speaker. However, I dare not express my ideas, especially in public. My best friend Lisa has been encouraging me accept the challenge.

    On her opinion, as long as I try my best, I will make it. After hear this, I have decided to have a try. I hope I will be luck.

We must save the trees and not buying things made of ivory.

He didn't give his advice to us, just sat there on silence.