Q. What is meant by biodiversity ? List two advantages of conserving forests and wildlife.​

the variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable.

Explanation:

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.