Fill in the following blanks with suitable words :
Near the earth's surface _____ air rises up whereas _____ air comes down .

Answer

To fill in the blanks in the given sentence, we can follow these steps:

1. **Identify the context**: The question is about the behavior of air near the Earth's surface, specifically which type of air rises and which type comes down.

2. **Understand the properties of air**: Warm air is less dense than cold air. This means that when air is heated, it becomes lighter and tends to rise.

3. **Fill in the first blank**: Since warm air rises, we can fill in the first blank with "warm".

4. **Fill in the second blank**: Since cold air is denser and tends to sink, we can fill in the second blank with "cold".

5. **Final sentence**: The completed sentence reads: "Near the earth's surface, warm air rises up whereas cold air comes down."

### Final Answer:
Near the earth's surface, **warm** air rises up whereas **cold** air comes down.

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