IF

例句：

1. 1.If you are late, you will miss the meeting.
   如果你迟到了，你将错过会议。
2. 2.If I were you, I would stay at home and study.
   如果我是你，我会待在家里学习。
3. 3. If it rains tomorrow, we will cancel the picnic.
   如果明天下雨，我们将取消野餐。