Here are the mistakes underlined along with their corrections:

1. **Mistake:** Jog is good exercise for the elderly.
**Correction:** Jogging is good exercise for the elderly.

2. **Mistake:** I have a headsdore now.
**Correction:** I have a headache now.

3. **Mistake:** Lack of exercise is harm to your health.
**Correction:** Lack of exercise is harmful to your health.

4. **Mistake:** Should I eating tofu?
**Correction:** Should I eat tofu?

5. **Mistake:** If you eats a lot of sweets, you will have a toothache.
**Correction:** If you eat a lot of sweets, you will have a toothache.

6. **Mistake:** The colour indicates when the fruits is ripe.
**Correction:** The colour indicates when the fruit is ripe.

7. **Mistake:** Cold weather results from chapped lips and skin.
**Correction:** Cold weather can result in chapped lips and skin. (optional correction)

8. **Mistake:** My mother usually cooks food with very few cooking oil.
**Correction:** My mother usually cooks food with very little cooking oil.

9. **Mistake:** We should have a balance diet for a long life.
**Correction:** We should have a balanced diet for a long life.