The function of a moderator in a nuclear reactor is:

The control rod in a nuclear reactor is made of

When $_3^7Li$ nuclei are bombarded by protons, and the resultant nuclei are $_4^8Be$, the emitted particles will be

When a proton collides with a $_3Li^7$ nucleus and results in a $_4Be^8$ nucleus,the emitted particle is:

For the following two nuclear reactions,the atomic number and mass number of nuclei $X$ and $Y$ are respectively:
$(I) \, _{92}^{235}U + _{0}^{1}n \rightarrow X + _{35}^{85}Br + 3 _{0}^{1}n$
$(II) \, _{3}^{6}Li + _{1}^{2}H \rightarrow Y + _{2}^{4}He$

During the nuclear fusion reaction,