In 1932, physicists engaged in studying the atom and its nucleus had only three particles to consider: the proton, the neutron ,and the electron.
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Each member(成员) has a switch with which to indicate a YES or NO vote(投票).
A text-book writer does not have available the material on which to base a reasonable conclusion as to who the credit(感谢) belongs.
The use of trigonometry(三角学) to describe the electrical signal has proved very valuable for engineers.
There is found to be a radial electrostatic field (径向静电场) near the earth’s surface.