The gas above `T_(c )` cannot be liquefied.

Explanation

To solve the question, we need to understand the concept of critical temperature (Tc) in the context of gases and their ability to be liquefied.

### Step-by-Step Solution:

1. **Define Critical Temperature (Tc)**:
- Critical temperature is the highest temperature at which a substance can exist as a liquid. Above this temperature, no amount of pressure can cause the gas to liquefy.

2. **Understand the Behavior of Gases**:
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