Given a scientific passage and an answer, generate a question for the given answer.
--------
Question: Passage: The Moon has no atmosphere. With no atmosphere, the Moon is not protected from extreme temperatures. The average surface temperature during the day is approximately 107C (225F). Daytime temperatures can reach as high as 123C (253F). At night, the average temperature drops to -153C (-243F). The lowest temperatures measured are as low as -233C (-397F). Answer: atmosphere

Answer: What does the moon not have to protect it from extreme temperatures?

Question: Passage: Membranes Biological membranes surround cells and serve to keep the insides separated from the outsides. They are formed of phospholipid bilayer1 s, which by definition are a double layer of fatty acid2 molecules (mostly phospholipid3 s, lipids containing lots of phosphorus). Proteins4 serve very important functions in cellular membranes. They are active transports in and out of the cell, acting as gatekeepers. They relay signals in and out of the cell. Proteins are the site of many enzymatic reactions in the cell, and play a role in regulation of cellular processes. Answer: biological membranes

Answer: What is it that surrounds cells and serve to keep the insides separated from the outsides?

Question: Passage: The speed of sound also depends on the temperature of the medium. For a given medium such as air, sound has a slower speed at lower temperatures. You can compare the speed of sound in air at different temperatures in Table below . A lower temperature means that particles of the medium are moving more slowly, so it takes them longer to transfer the energy of the sound waves. The amount of water vapor in the air affects the speed of sound as well. Do you think sound travels faster or slower when the air contains more water vapor? ( Hint: Compare the speed of sound in water and air in Table above . ). Answer: sound

Answer:
The amount of water vapor in the air and the temperature of the medium affects how fast what travels?