A:We mustn't smoke here.
B:Keep quiet.
C:We mustn't run.
- How long does it take to get to the airport?
- Forty minutes. But it's foggy today. I'm not sure _________ the highway will be closed soon. Let's set off earlier.
鲁迅先生说:“挖出地下的煤来,就足够全世界使用数百年,但是数百年后呢?我们当然是或上了天堂,或下了地狱,但我们的子孙后代,却是要生存的……”鲁迅先生是要告诉我们( )
①资源问题关系到人类的生存和发展 ②资源具有数量有限的特点
③煤是一种可再生资源,要合理开发和利用 ④资源的开发还应考虑后代人的需要