What is the branch of earth science that puts past events on earth in order by time?
A) geology
B) geography
C) ecology
D) chronology

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c. ozone layer hole d. increase in sea levels

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

In which part of the body is a ball-and-socket joint found?