Sure! Here are the mistakes underlined along with their corrections:

1. "School ahead” sign means there are **a** school ahead.
**Correction:** "School ahead” sign means there **is** a school ahead.

2. The roads in Mumbai are **narrow**.
**Correction:** The roads in Mumbai are **narrow**.

3. Some people don’t **obey** traffic rules.
**Correction:** Some people don’t **obey** traffic rules.

4. My father taught me **how** to ride a bike.
**Correction:** My father taught me **how** to ride a bike.

5. Where should pedestrians **cross** the street?
**Correction:** Where should pedestrians **cross** the street?

6. Which lane should you use when **riding** a bike?
**Correction:** Which lane should you use when **riding** a bike?

7. Hoang is riding a bike, and he is **wearing** a helmet.
**Correction:** Hoang is riding a bike, and he is **wearing** a helmet.

8. It is raining hard, but Mr. David is driving **quickly**.
**Correction:** It is raining hard, but Mr. David is driving **quickly**.

9. Mr. Jack is not safe because his daughter was sitting in front of him.
**Correction:** (This sentence is correct but could be improved for clarity if needed.)

10. How does your dad get to work?
**Correction:** How does your dad get to work?