TASK DEFINITION: In this task, you are given a paragraph, and your task is to construct a question from the given passage. Construct question in such a way that (i) it is well explained in the paragraph, (ii) the words may/may not be present in the paragraph, (iii) it should start with what/how/describe. Avoid creating a question that (i) is just relevant to one or two sentences, and (ii) not relevant to passage. 
PROBLEM: Water comes into contact with something made of iron. The water combines with carbon dioxide in the air to form carbonic acid. As the acid is formed, the iron starts to dissolve. Some of the water breaks down into hydrogen and oxygen. The free oxygen and dissolved iron bond together. They form iron oxide, which is rust. 

SOLUTION: How does rust form?

PROBLEM: Pack up your camping gear, food, and clothes. Drive to your campsite. Set up your tent. Start a fire in the fire pit. Cook your food in the fire. Put the fire out when you are finished. Go to sleep. Wake up. Put away your tent. Drive home. 

SOLUTION: Describe the typical steps involved in camping.

PROBLEM: People separate different materials to be recycled. The recyclable materials go to a recycling center. The recycling center further separates the materials. Large equipment compacts the materials into bales. The recyclable materials are shipped to other recycling centers. The other recycling centers further process the materials that center specializes in. The materials are purchased by manufacturers. The manufacturers process the recycled materials the same way they would use new materials. The recycled materials are incorporated into new products. 

SOLUTION:
How does recycling work?