are filled with special absorbing elements that move up and down between the uranium rods to keep the atoms from getting out of control.

The correct answer is - control rods.

Explanation:

Control rods are filled with special absorbing agents such as boron, cadmium, silver, and others to absorb as many neutrons as to control the fission reaction by moving them up and down in between uranium rods.

These control rods are used to prevent the nuclear reaction from getting out of control in the nuclear plant or reactor by absorbing the neutrons and prevent uranium to convert.

idk i’m struggling too

sorry i was late, but i don't know what assignment your talking about, i'm in flvs as well, im in earth space science. but u are behind pace bc every class should be in the 3's or 4'