Muscular strength is how much you can lift/push/pull, ect. Muscular endurance is how long you can do something with your muscles. Like if you have to put your are straight out in front of you and hold a 25 pound dumbbell. Your will get tired and give out. the more Muscular endurance you have the longer you can do something with your muscles.
It will help by creating a well balanced meal, and by keeping your exercise balanced
I'm sure the answer you are looking for is specific to your class, but I would say that the nurse should provide something like, "The tumor is most likely benign, but until we test further, we can't know if it's malignancy."
A. Oxygen, this is why it is very important to keep breathing while exercising.