Which system is affected when tobacco reduces the flow of oxygen to the brain, potentially leading to a stroke?
a.
circulatory system
b.
excretory system
c.
respiratory system
d.
nervous system

If you were running a marathon, which type of muscle fibers would be most useful to you? a. slow-twitch b. fast-twitch, type i a c. intermediate-twitch, type ii b d. slow-intermediate twitch, type i b select the best answer from the choices provided. a b c d