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: Coal is burned in a boiler. Steam is produced under pressure. Flows into a turbine. The turbine spins. Creates electricity. 

SOLUTION: How does a coal-fired power plant work?

PROBLEM: Comets fly around in outer space. A comet flies close to a planet. The comet enters the planet's atmosphere. The comet crashes into the planet. The energy of the impact creates a hole on the planet. 

SOLUTION: Describe how meteorites create craters on a planet.

PROBLEM: Water vapor is in warm air. The warm air cools. The warm air expands. The water vapor in the air condenses. The water vapor forms water droplets or ice crystals. 

SOLUTION:
How are clouds formed?