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. 

Input: Consider Input: Fuel is converted to energy when air and petrol mix. The car engine burns the mix of air and petrol. Hot gas from the burning pushes the pistons. The resulting energy powers the crankshaft. Crankshaft powers the gears. The gears make the wheels roll. 

Output: Describe how a car works


Input: Consider Input: Waste products are deposited in the blood. Blood is carried to the kidneys through the renal arteries. The kidneys contain filters inside. The filters capture the waste products. The waste is combined with water to make urine. The urine leaves the kidney and is collected in the bladder. The cleaned blood is returned to the body. 

Output: Describe how kidneys work


Input: Consider Input: Fault lines appear underground. The fault lines grow over time. The rocks on each side of the fault lines rub against the rocks on the other side of the fault line. The rocks put pressure on each other. The rocks break from the pressure. The breaking of the rocks releases a lot of energy. The energy causes seismic waves. The seismic waves make the earth shake. 


Output: How do earthquakes occur?