Every living thing needs ___ to surve.
-water
-carbon dioxide
-oxygen

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

Ablastocyst is a group of cells that forms after a human egg is fertilized. the blastocyst consists of two types of cells. some of these cells will become the placenta. what do the other cells develop into?

Greenthe fossil record is the history of life recorded byhuman observationgod.climatologists.remains of the past.