In a cathode ray tube, the number of electrons that reach the fluorescent screen is controlled by the
a. deflecting plate.
b. anode.
c. grid.
d. cathode.

Grid 

The cathode serves as the positive terminal and the anode as the negative terminal. The flow of electrons is from the cathode to the anode.The relationship between a cathode and an anode involves electrons. An example of this is reaction that takes place in an electrolytic cell. It has a cathode compartment, an anode compartment and a salt bridge that divides the compartment. The movement of electrons is from the cathode to the anode. 

Engineers have contribute to society in many ways like making the technology we use today or any type of power energy material