Computers were ________(发明)not long ago, but they are popular now.
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.