The principal grassland of South America is ..............

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Grassland Ecosystems**: Grasslands are ecosystems where grasses (monocots) dominate the landscape. These areas typically have few trees, which are scattered and do not form a dense canopy.

2. **Characteristics of Grasslands**: In grassland ecosystems, the trees are not close enough to each other to block sunlight, which allows grasses to thrive. This environment is characterized by a specific type of vegetation and climate.

3. **Types of Grasslands**: There are various types of grasslands around the world, such as savannas and steppes. Each type has its unique characteristics based on geographical location and climate.

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