What are weeds? How can we control them?

Explanation

### Step-by-Step Solution:

1. **Definition of Weeds**:
- Weeds are undesirable plants that grow alongside cultivated crops in agricultural fields. They compete with crops for essential resources.

2. **Impact of Weeds on Crops**:
- Weeds compete with crops for nutrients, space, and light. This competition can lead to reduced growth and yield of the crops, ultimately affecting agricultural productivity.

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