In cold countries …………is used as an anti-freezing agent in the radiator of car.

Answer

To solve the question, "In cold countries, …………is used as an anti-freezing agent in the radiator of car," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a substance that is used as an anti-freezing agent in car radiators, particularly in cold countries.

2. **Defining Anti-freezing Agent**: An anti-freezing agent is a substance that lowers the freezing point of a liquid. This is important in car radiators to prevent the coolant from freezing in cold temperatures.

3. **Identifying Common Anti-freezing Agents**: The most commonly used anti-freezing agents in car radiators are ethylene glycol and propylene glycol. These substances are mixed with water to create a coolant that remains liquid at lower temperatures.

4. **Choosing the Correct Anti-freezing Agent**: Among the common anti-freezing agents, ethylene glycol is widely used due to its effectiveness and availability. It is specifically known for its ability to significantly lower the freezing point of water when mixed.

5. **Final Answer**: Therefore, the substance used as an anti-freezing agent in the radiator of cars in cold countries is **ethylene glycol**.