Forests are home to a wide variety of plants, animals, insects and birds.
Fill in the blank:
(a) The insects, butterflies, honeybees and birds help flowering plants in _______.
(b) A forest is a purifier of _______ and ________.
(c) Herbs form the ________ layer in the forest.
(d) The decaying leaves and animal droppings in a forest enrich the _______.
Explain why there is a need of variety of animals and plants in a forest.