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

Passage: They are ectothermic , meaning their temperature depends on the temperature of their environment. Ectothermic animals are cold-blooded in that they cannot raise their body temperature on their own. This is unlike humans, whose temperature is controlled from inside the body. Answer: ectothermic
What is the term for animals that cannot raise their body temperature on their own?

Passage: Volatile organic compounds (VOCs) are carbon compounds such as methane. VOCs are released in many human activities, such as raising livestock. Livestock wastes produce a lot of methane. Answer: methane
The waste of cows releases a lot of which type of gas?

Passage: The pressure of gases in the atmosphere is greatest at sea level and decreases rapidly as altitude increases. Answer: sea level
Where is the pressure of gases in the atmosphere at its greatest?