Bob and Jim have been good friends (自从) they joined the same tennis team.
句子翻译
每天锻炼一小时对健康和学习都有好处.
没有什么能阻止我们实现梦想.
他们从小学起就一直是好朋友.
The machine is hard to (控制). There must be something wrong with it.
Professor Xu gave us a talk on how to (保护) the environment last week.