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

Q: Passage: To help digest the large amount of plant material, the stomach of the ruminants is a multi-chambered organ, as illustrated in Figure 34.8. The four compartments of the stomach are called the rumen, reticulum, omasum, and abomasum. These chambers contain many microbes that break down cellulose and ferment ingested food. The abomasum is the "true" stomach and is the equivalent of the monogastric stomach chamber where gastric juices are secreted. The four-compartment gastric chamber provides larger space and the microbial support necessary to digest plant material in ruminants. The fermentation process produces large amounts of gas in the stomach chamber, which must be eliminated. As in other animals, the small intestine plays an important role in nutrient absorption, and the large intestine helps in the elimination of waste. Answer: four

A: How many stomach compartments do ruminants have?
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Q: Passage: The male gametophyte produces flagellated sperm that must swim to the egg formed by the female gametophyte. For this reason, sexual reproduction must happen in the presence of water. Therefore, nonvascular plants tend to live in moist environments. Though the life of a nonvascular seedless plant is a cycle, this can be considered the initial step in the life cycle. Answer: water

A: When flagellated sperm must swim to the egg, sexual reproduction requires the presence of what substance?
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Q: Passage: Sound is the transfer of energy from a vibrating object in waves that travel through matter. Answer: matter

A:
Sound is the transfer of energy from a vibrating object in waves that travel through what?
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