Most of the electronic devices of this kind , ____ manufactured for this purposes , are tightly packed.

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Ionization energy is the amount of energy required to remove an electron from an isolated atom. For a hydrogen atom, composed of an orbiting electron bound to a nucleus of one proton, how much ionization energy is required to force the electron from its lowest energy level entirely out of the atom?

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单选题

If a 500keV photon enters an atom that has a binding force of 50keV and removes an electron by giving it an energy of 50keV, then the new photon would have an energy of 400keV.

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单选题

Which of the following grammar activities is most communicative?

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单选题

The Indo-European language family is made up of most of the languages of Europe, the Near East, and ______ . ( )

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Which of the following is the most famous of all British newspapers?

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