instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Hair, hair follicle, and oil glands. The oil, called sebum, helps to prevent water loss from the skin. The sebaceous gland secretes sebum, which waterproofs the skin and hair. Answer: sebum
answer:
What does the sebaceous gland secrete which waterproofs the skin and hair?

question:
Passage: When heat is positive, the total energy of the system is increasing. Answer: it increases
answer:
What happens to the total energy of the system when heat is positive?

question:
Passage: Ulcers are sores in the lining of the stomach or duodenum that are usually caused by bacterial infections. They may also be caused by the acidic environment of the stomach. Stomach acids may damage the lining of the stomach. Symptoms typically include abdominal pain and bleeding. You can see how stomach ulcers develop at this link: http://www. youtube. com/watch?v=4bXZRgJ-1fk . Answer: ulcers
answer:
What are sores in the lining of the stomach or duodenum that are usually caused by bacterial infections or acidity?