The materials which can withstand very high temperature without melting or becoming soft are called……………….. . These are used in making …………….of furnaces.

Options

A. refractory materials, inner lining
B. flux, base
C. brick materials , outer structure
D. mica, outer lining.

Answer

### Step-by-Step Solution:

1. **Identify the Type of Materials**: The question asks for materials that can withstand very high temperatures without melting or becoming soft. These materials are known for their ability to maintain their structural integrity under extreme heat.

2. **Define the Term**: The specific term for these materials is "Refractory materials." Refractory materials are designed to resist heat and are used in various high-temperature applications.

3. **Examples of Refractory Materials**: Common examples of refractory materials include magnesium oxide (MgO) and zinc oxide (ZnO). These materials have very high melting points, making them suitable for high-temperature environments.

4. **Application of Refractory Materials**: Refractory materials are primarily used in the construction of furnaces. They are utilized for the inner lining of furnaces to protect the structural components (often made of materials like steel) from the extreme heat generated during operation.

5. **Conclusion**: Therefore, the complete answer to the question is:
- The materials which can withstand very high temperature without melting or becoming soft are called **Refractory materials**. These are used in making **the inner linings of furnaces**.