instruction:
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. 
question:
Stars burn mass. The star burns until it runs out of fuel. The star can no longer support its weight. The layers of hydrogen press down on the core. The core gets smaller and smaller under the pressure. The pressure causes gravity to get stronger. The gravity becomes so powerful that nothing can escape it. Anything that gets close to it, is drawn into it by its gravity. Light is drawn into it. Light can not escape. 
answer:
How is a black hole formed?


question:
The virus finds an animal cell. The virus attaches to the cell's surface. The cell swallows the virus. The virus' RNA is released into the cell. The cell mistakenly reads the virus' RNA instead of its own. The cell creates new viruses. The animal cell releases the new viruses. The new viruses can infect more cells. 
answer:
How does a virus infect an animal?


question:
You inhale air through your nose and mouth. The air travels down into your lungs. Oxygen from the air goes into your bloodstream. Oxygen circulates throughout the body due to the heart's pumping. Carbon dioxide travels from the blood into the lungs. Carbon dioxide travels from the lungs up the windpipe. Carbon dioxide is exhaled. 
answer:

Describe the process of breathing.