Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: There are three types of mechanical waves. They differ in how they travel through a medium. The three types are transverse, longitudinal, and surface waves. All three types are described in detail below. Answer: three

Answer: How many types of mechanical waves are there?

Question: Passage: Equinox comes halfway between the two solstices. At equinoxes, the Sun's rays shine most directly at the Equator ( Figure below ). The daylight and nighttime hours are exactly equal on an equinox. The autumnal, or fall, equinox happens on September 22 or 23. The vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Answer: equinox

Answer: What event occurs between the two solstices?

Question: Passage: Genes play an important part in determining our adult height. However, factors such as poor nutrition can prevent us from achieving our full genetic potential. Answer: nutrition

Answer:
What factor other than genes is important in determining adult height?