英语翻译1.当时我看到一只猫跑过马路2.我们应该保持教室清洁（keep）3.客人已经到了4.她想出了一个好主意5.我们听

1.At that time I saw a cat run across the road.
2.We should keep the classroom clean.
3.The guest has arrived.
4.She's come up with a good idea.
5.We heard her singing in the lobby.
作为参考,第1句中的run最好用原形,see sb/sth do sth,侧重目睹了事件的全过程.原句中的跑过很明显说明看到了猫从马路一边跑到另一边.相应的,第5句中用进行时侧重事情正在发生.