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. 
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Question: Animals and plants die in soft soil or mud. Sediment builds up over the remains. The remains decompose, leaving only trace amounts. The remaining parts over the years are replaced with mineral. A fossil is formed. 

Answer: Describe the process of fossilization


Question: During evaporation the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air. Water vapor in the air gets cold and changes back into liquid, forming clouds, which is called condensation. Precipitation occurs when so much water has condensed that the air cannot hold it anymore. Water falls back to the earth in the form of rain, hail, sleet or snow. When water ends up on land, it will either soak into the earth and become part of the "ground water" for animals or plants to drink. It may also run into the oceans, lakes, or rivers where the cycle starts again. 

Answer: Describe the process of precipitation


Question: A fuel is heated in an oven. Above the oven is a tank of water that is sealed. The tank of water begins to boil above the oven. A the water boils steam is created. The steam is denser than air so it needs a place to go. The steam is forced out of the tank and into a piston. The piston moves up. The valve of the piston closes. The valve on the next piston opens. The steam fills the next piston, driving it up, and the other one down. 

Answer:
How does a steam engine work?