Which one of the following forms of energy leads to least environmental pollution in the process of its harnessing and utilisation?

Give two uses of coke.

Write down three advantages of harnessing wind energy.

Vinod is a member of the school Eco-club. He knows about a school that is a zero-garbage zone. He expressed his willingness to his teachers to implement the same in his school. He decided to place different coloured dustbins for segregating biodegradable and non-biodegradable garbage as the first step. Now answer the following questions.
$(a)$ Why does Vinod want to segregate biodegradable and non-biodegradable waste?
$(b)$ What can Vinod do with the biodegradable waste?

Why are solar cookers covered with a glass plate?

What type of energy is utilized by a sailing boat?