Answer:
the answer would be cause and affect. when the oxygen is added to the rats environment the rat can breathe so when it is added the rat will start to breathe causing the rat to change its behavior. when there is no oxygen the rat cant breathe most likely causing the rat to panic because there is no air so when air is added the panicked rat would stop panicking because now it can breathe again
Explanation:
Edmund Kells constructed his own x-ray machine.
FiRst person .... I believe
