All the circulating red blood cells originate in the
a) thymus.
b) spleen.
c) lymph tissue.
d) heart.
e) red bone marrow.

Diminishing of the ozone

Agroup of engineering students from purdue university reported that its licking machine, modeled after a human tongue, took an average of 364 licks to get to the center of a tootsie pop. twenty of the group's volunteers assumed the licking challenge-unassisted by machinery-and averaged 252 licks each to the center.