Which of the following are environment-friendly practices?

Explanation

### Step-by-Step Solution:

1. **Identify Environment-Friendly Practices**: The question asks us to identify practices that are friendly to the environment. We need to analyze the given options to determine which ones contribute positively to our ecosystem.

2. **Evaluate Each Option**:
- **Option 1: Carrying Cloth Bags**: This practice is environment-friendly because it reduces the use of plastic bags, which are non-biodegradable. Cloth bags can be reused multiple times and are biodegradable, making them a sustainable choice.
- **Option 2: Switching Off Unnecessary Lights and Fans**: This practice helps in conserving electricity. Since a significant portion of electricity is generated from fossil fuels, reducing electricity consumption decreases the burning of these fuels, which in turn reduces air pollution.
- **Option 3: Walking to School Instead of Using a Scooter**: This practice conserves fossil fuels by reducing the reliance on vehicles that run on petrol or diesel. It also helps in reducing air pollution caused by vehicle emissions.
...