Fill in the blanks by suitable words to make correct statements:
Substances which cannot be decomposed by micro-organisms are called _______ substances.

Explanation

To fill in the blank in the statement "Substances which cannot be decomposed by micro-organisms are called _______ substances," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a term that describes substances that cannot be broken down by microorganisms.

2. **Identifying Key Terms**: We need to focus on the words "cannot be decomposed" and "micro-organisms." This indicates we are looking for a specific category of substances.

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