Where is dissolved oxygen likely to be lowest

a) at the bottom of a deep lake
b) in the fastest part of a stream
c) along the edge of a fast river
d) at the surface of a tidal pool

In iceland, the mid atlantic ridge runs through the center of the contry. what can you conclude about the apperence of iceland many thousands of years from now?

Up until 1938, paleontologists accepted the idea that coelacanths (an ancient fish) went extinct at the time that they last appear in the fossil record, about 80 million years ago. but in 1938, a live coelacanth was discovered off the coast of south africa that was compared to the fossil record and found to be the same species what goal of science does this discovery represent

Ronald wants to see if a new shower cleaner works better in removing soap than his old cleaner. he uses the new cleaner on one half of the shower tiles and his old cleaner on the other half. identify the independent and dependent variables in this experiment. enter your answer in the space provided.