1: Their teacher will sad if they don't ass the exam

2: If you don't say sorry, they won't forgive you

3: If you wanted to be healthy, you shouldn't continue smoking

4: The plants may not need fertilezer if the soil is rich

5: You cannot buy this watch if you don't have enough money

1. if they don't pass the exam , their teacher will sad 

2. if you not say sorry , they will not forgive you

3. if you wanted healthy , you shouldn't continue smoke 

4. if soil riched , the plants mayn't need fertilizer

5. if you don't have enough money , you can't buy this watch