TASK DEFINITION: Given a scientific passage and an answer, generate a question for the given answer.
PROBLEM: Passage: Cynodonts probably gave rise to mammals about 200 million years ago. However, they are not considered to be mammals themselves. In fact, competition with early mammals may have led to their extinction. They went extinct sometime during the Jurassic or Cretaceous Period. Answer: mammals

SOLUTION: Competition with what emerging animal group may have led to extinction of cynodonts about 200 million years ago?

PROBLEM: Passage: If water is so simple, why is it special? Water is one of the few substances that exists on Earth in all three states of matter. Water occurs as a gas, a liquid and a solid. You drink liquid water and use it to shower. You breathe gaseous water vapor in the air. You may go ice skating on a pond covered with solid water ice in the winter. Answer: three matter states

SOLUTION: In how many states does water exist on earth?

PROBLEM: Passage: The human brain is an amazing organ. It is the most complex organ in the human body. By adulthood, the brain weighs about 3 pounds and consists of billions of neurons. All those cells need a lot of energy. In fact, the adult brain uses almost a quarter of the total energy used by the body!. Answer: brain

SOLUTION:
What is the most complex organ in the human body?