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.

Waste builds up in the blood. Blood enters the kidney. Blood passes through nephrons in the kidney. Different kinds of waste are momentarily trapped in the kidney. Cleaned blood flows out of the kidney. Filtered waste accumulates in liquid form (urine). Urine flows out of the kidney into the bladder.
Describe what kidneys do

Solution caves are formed in limestone and similar rocks by the action of water. After a rain, water seeps into cracks and pores of soil and rock. The water percolates beneath the land surface. Some of the water reaches a zone where all the cracks and pores in the rock are already filled with water. Rainwater absorbs some carbon dioxide as it passes through the atmosphere and even more as it drains through soil and decaying vegetation. The water combines chemically with the carbon dioxide. A weak carbonic acid solution is formed. This acid slowly dissolves calcite, forms solution cavities, and excavates passageways.
Describe the process of desalination

Sugar enters the body. Bloodstream. The pancreas. Insulin lower sugar levels. Bloo sugar goes back to normal.
How does the body control its blood sugar level?