Cepheids: brighten and dim periodically
can be used to measure stellar distance
have been discovered in galaxies other than our own
all of the above

b, acidosis

acidosis is when the human body attempts to return the bloods ph levels back to normal when the blood is acidic

answer; 60-100; beats per minute

answer; the above answer to the above statement is (true)

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands