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

Q: Passage: Steel is an example of an alloy. An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is a solid solution. It is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Several other examples of alloys and their uses are shown in Figure below . You can learn about an amazing alloy called memory wire at the URL below. If you have braces on your teeth, you may even have this alloy in your mouth!. Answer: an alloy

A: A mixture of a metal with one or more other elements is called?
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Q: Passage: In order to study these characteristics, Mendel needed to control the pollination of the pea plants through artificial fertilization . Pollination occurs when the pollen from the male reproductive part of a flower, called the anthers , is transferred to the female reproductive part of a flower, called the stigma . Pea plants are self-pollinating , which means the pollen from a flower on a single plant transfers to the stigma of the same flower or another flower on the same plant. In order to avoid self-pollination, Mendel removed the anthers from the flowers on a plant. He then carefully transferred pollen from the anthers of another plant and using a small paintbrush, dusted the pollen onto the stigma of the flowers that lacked anthers. This process caused cross-pollination. The Figure below shows the location of the male and female parts of a flower. Cross-pollination occurs when pollen from one flower pollinates a flower on a different plant. In this way, Mendel controlled the characteristics that were passed onto the offspring. The product of cross-pollination is known as a hybrid. The ability to cross-pollinate pea plants allowed Mendel to study the offspring of two parents with different traits, such as a tall stem or a short stem. Answer: pollination

A: The process of transferring pollen from the male reproductive part of a flower known as the anthers to the female reproductive part of the flower known as the stigma is referred to as what?
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Q: Passage: The corona ( Figure below ) is the outermost part of the Sun's atmosphere. It is the Sun's halo, or "crown. " With a temperature of 1 to 3 million K, the corona is much hotter than the photosphere. The corona extends millions of kilometers into space. Sometime you should try to see a total solar eclipse. If you do, you will see the Sun's corona shining out into space. Answer: corona

A:
What is the outermost part of the sun's atmosphere called?
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