Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: Ocean water also absorbs gases from the atmosphere. The most important are oxygen and carbon dioxide. Oxygen is needed by living things in the oceans. Much of the carbon dioxide sinks to the bottom of the seas. Carbon dioxide is a major cause of global warming. By absorbing carbon dioxide, the oceans help control global warming. At least as long as the carbon dioxide stays in the seas. Answer: carbon dioxide

Ex Output:
Oceans help control global warming by absorbing what?

Ex Input:
Passage: Acidity is measured on a pH scale. Rain that is 5.0 or less on that scale is considered acid rain. Answer: ph scale

Ex Output:
Acidity is measured on what kind of scale?

Ex Input:
Passage: Your body needs proteins to create muscles, regulate chemical reactions, transport oxygen, and perform other important tasks in your body. But how are these proteins built? They are made up of units called amino acids. Just like there are only a few types of blocks in a set, there are a limited number of amino acids. But there are many different ways in which they can be combined. Answer: proteins

Ex Output:
What is needed to create muscles, regulate chemical reactions, and transport oxygen?