Advantages and disadvantages of rusting of metals

What are the advantages and disadvantages of using fertilizers?

Compare and contrast the advantages and disadvantages of production of genetically modified crops.

What are the advantages and disadvantages of using charcoal as a fuel as compared to wood ?

Distinguish between fertilizer and manure. Give suitable examples. What are advantages and disadvantages of using fertilizer ?

What are the advantages and disadvantages of using a solar cooker ? Are there places where solar cookers would have limited utility ?