Which word would change the meaning of the selection above if it replaced "variations"?
a
differences
b
changes
c
shifts
d
bends

Which of the following will not cause mass extinction? a. drastic change is weather b. geological change c. both a and b d. none of the above

Which symbols below represent the ions found in the glass of water ? a. oh- and h+ b. co2 and o2 c. o2 and h2 d. nh3- and h+

The many stone tools, fragmentary animal bones, and teeth found at gran dolina, spain, indicate that hominids there? a. processed and consumed animals and other hominids. b. did not differ appreciably from earlier asian homo erectus. c. were similar to later homo sapiens. d. none of the above