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

Example Input: 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
Example Output: A mixture of a metal with one or more other elements is called?

Example Input: Passage: Most gemstones are not used exactly as they are found in nature. Usually, gems are cut and polished. Figure below shows an uncut piece of ruby and a ruby that has been cut and polished. The way a mineral splits along a surface allows it to be cut to produce smooth surfaces. Notice that the cut and polished ruby sparkles more. Gems sparkle because light bounces back when it hits them. These gems are cut so that the most amount of light possible bounces back. Other gemstones, such as turquoise, are opaque, which means light does not pass through them. These gems are not cut in the same way. Answer: opaque
Example Output: What are gemstones known as when light cannot pass through them?

Example Input: Passage: Cycloalkanes are hydrocarbons whose molecules are closed rings rather than straight or branched chains. A cyclic hydrocarbon is a hydrocarbon with a ring of carbon atoms. Answer: carbon atoms
Example Output:
Cycloalkanes are hydrocarbons whose molecules are closed rings rather than straight or branched chains. a cyclic hydrocarbon is a hydrocarbon with a ring of these?