Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Some meteorites are made of iron and nickel and are thought to be very similar to the core of the earth.

Answer: Some meteorites are made of iron and nickel and are thought to be very similar to what part of the earth?


Question: Together, the muscular and skeletal organs are known as the musculoskeletal system.

Answer: Together, the muscular and skeletal organs are known as what?


Question: Nuclei with even numbers of protons, neutrons, or both are more likely to be stable.

Answer:
Nuclei with even numbers of protons, neutrons, or both are more likely to be this?