TASK DEFINITION: Given a scientific passage and an answer, generate a question for the given answer.
PROBLEM: Passage: Insight learning , which is based on past experience and reasoning, is a hallmark of the human animal. Humans have used insight learning to solve problems ranging from starting a fire to traveling to the moon. It usually involves coming up with new ways to solve problems. Insight learning generally happens quickly. An animal has a sudden flash of insight. Insight learning requires relatively great intelligence. Human beings use insight learning more than any other species. They have used their intelligence to solve problems ranging from inventing the wheel to flying rockets into space. Answer: insight

SOLUTION: What type of learning is based on past experience and reasoning?

PROBLEM: Passage: Most chemical reactions in organisms take place in an environment that is mostly water. Answer: water

SOLUTION: The environment where most chemical reactions in organisms takes place consists mostly of what?

PROBLEM: Passage: Facilitated Diffusion Across a Cell Membrane. Channel proteins and carrier proteins help substances diffuse across a cell membrane. In this diagram, the channel and carrier proteins are helping substances move into the cell (from the extracellular space to the intracellular space). Answer: cell membrane

SOLUTION:
Channel proteins and carrier proteins help substances diffuse across what?