Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Q: The pressure of a sample of gas is measured with an open-end manometer.

A: The pressure of a sample of gas is measured with an open-end what?
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Q: Ionic compounds contain cations and anions rather than discrete neutral molecules.

A: Ionic compounds contain cations and anions rather than what?
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Q: Mrna is the message sent from the nucleus to the ribosome.

A:
What is the message sent from the nucleus to the ribosome?
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