Question: You are presented with the quiz "Sleep has what impact on health?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "rest has a positive impact on a health" and "enhances sleep patterns and supports restful sleep".   So, what's the best answer to the question?
Answer: positive

Question: You are presented with the quiz "What can be done to water to remove harmful substances before drinking?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "treating water is used to remove harmful substances before drinking" and "boiling is the safest method of treating water".   So, what's the best answer to the question?
Answer: Boiling it

Question: You are presented with the quiz "How do you keep a cup hot?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "insulated material can be used for keeping warm" and "an insulated cup with a cover is great for keeping beverages warm".   So, what's the best answer to the question?
Answer:
insulation