The correct answers are:
- plants;
- trees;
- grass;
The plants, trees, grasses, shrubs, are all things that are cooling the area i which they are naturally. The reason for this is that they do not allow most of the sunlight to reach the surface of the ground, so they absorb some of it, and reflect some of it. The trees with their canopies are the once that manage to contribute the most for the cooling, as they keep the sunlight several meters, or even several tens of meters, above the ground. Though the plants, shrubs, and grasses also do their job, even though it is not to such a high extent.