Question

what is the most effective way to protect dry lands from desertification?
terrace farming
mine digging
planting a tree belt
constructing a dam

Explanation:

Terrace farming is for sloped - land soil conservation, mine digging can cause environmental damage, constructing a dam is mainly for water management like flood control and water storage. Planting a tree belt can fix the soil, reduce wind erosion and retain moisture, which is effective in preventing desertification in dry lands.

Answer:

C. planting a tree belt