Answer:
To swim faster
Reducing the drag. As with all the other tips here this one is not about how strong you are as the right technique smoothes out your swimming using your strength in a much more efficient way.
Work on your kicks.
Secrets of good propulsion.
Balance
Slightly spread your fingers.
I think what your answer is would be Amphibians? I could be wrong.
Hope this Helps! :)
(1) they keep toxic substances out of the cell;
(2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment;
(3) they separate vital but incompatible metabolic processes conducted within organelles.
D)
Because a scientific theory is something that has been proven over the trials of many tests
Hope that helps :)