Which of the following is true about acid rain?
a. it is more acidic that normal rain.
b. it is less acidic than normal rain.
c. all rain is acid rain.
d. there is no such thing as acid rain.

For this question look at the hydropic diagram water that is heated by the sun evaporates. select the number that represents it.

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

Which short-term environmental changes would a very small asteroid or comet impact on earth most likely cause? check all that apply. flooding extinction craters on surface changes in weather patterns death of organisms and populations