Which ecosystems are called backbone of entire civilization ?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question:**
- The question asks which ecosystems are referred to as the backbone of civilization. This indicates we need to identify ecosystems that are essential for human survival and societal development.

2. **Identifying Key Needs of Civilization:**
- To sustain a civilization, certain fundamental needs must be met. The most critical need is food, as it is essential for survival.

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