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: Rainwater picks up carbon dioxide from the air. Rainwater goes into soil. Water with carbon dioxide percolates through soil. The water becomes a weak acid. The water dissolves limestone. Caves form where the limestone was dissolved.

SOLUTION: How do caves form?

PROBLEM: Water gets caught in winds that are moving upward. The water freezes. The water starts to fall. The winds are strong enough from keeping it from falling back to earth. This pattern of rising and falling continues. The hail becomes too large to be pushed up by the wind. The hail finally falls to the ground.

SOLUTION: How does hail form?

PROBLEM: A star burns in space. Eventually it burns all its hydrogen. Becomes a red giant. Once the red giant burns itself out. The core of the star collapses. The gasses will start to disperse. Only the core is left. A white dwarf has been formed.

SOLUTION:
How is a white dwarf star formed?