既然我们还有几分钟才看电影，那就喝杯咖啡吧。

___Since we have a few minutes before the movie starts, let's grab a coffee.

因为我妈妈明天要做个小手术，所以我不能来上您的课了。

___Since my mother has a small surgery tomorrow, I won't be able to come to your class.

既然你已经完成了作业，那就可以玩电子游戏了。

___Since you've finished your homework, you can play video games.