I. 改写句子 使用省略手段避免下面各句重复与冗赘:
1. Someone has used my mobile phone, but I don’t know who has used it.
2. John worked hard but his brother did not work hard.
3. I have lazy students and hardworking students in my class.
4. --- Has he ever been abroad?
--- No, he has never been abroad.
