instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: An important function of the circulatory system is transporting oxygen to cells. Answer: circulatory system
answer:
Which system transports oxygens to cells?

question:
Passage: Soil is a precious resource. It allows us to grow food and the materials we use to make everything from the shirt you have on to the medicine you took this morning. Soil is made up of small pieces of rock that have broken down over hundreds, if not thousands, of years. Soil is also partly made up of the remains of plants and animals, and is home to many organisms, from earthworms to ants. But soil can be damaged by unsustainable farming practices and clear-cut logging. In this chapter, you will learn how soil forms, what it contains, and how to protect it. Answer: soil
answer:
What precious resource allows us to grow food as well as materials we turn into clothing and medicine?

question:
Passage: Conditioning is a way of learning that involves a reward or punishment. If you ever trained a dog to obey a command, you probably gave the dog a tasty treat each time he performed the desired behavior. It may not have been very long before the dog would reliably follow the command in order to get the treat. This is an example of conditioning that involves a reward. Answer: conditioning
answer:
The way of learning that involves reward and punishment is called?