Atherosclerosis is defined as select one: a. the blockage of a coronary artery b. constriction of the blood vessels c. the buildup of plaque inside blood vessels d. dilation of the arteries

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere

The earth's oceans are made up of chlorine, and trace elements. a) carbon, oxygen b) oxygen, silicon c) hydrogen, oxygen d) nitrogen, oxygen

How do the sperm cells get from the stigma to the ovules?