Why do you think rheumatoid arthritis is often a degenerative disease?

Plato

Because the immune system considers the healthy tissue to be a foreign invader, every time the body regenerates the tissue, it will attack it again. Over time, there is greater tissue loss, which causes symptoms to worsen.

i say that the answer is 'd'

well, it depends. it is natural to not fall asleep before 11: 00 p.m. teens need about 8-10 hours of sleep each night to function best.

enjoy your day!