IF interconnection

例句：

1. 1. If you are not careful, you might fall down the stairs.
   如果你不小心，你可能会从楼梯上摔下来。
2. 2. If it rains tomorrow, we will have to cancel the picnic.
   如果明天下雨，我们将不得不取消野餐。
3. 3. If you need help, just ask me.
   如果你需要帮助，就问我吧。