Fish have scales that enable them to live in a water environment. this is an example of

Adaptation

Explanation:

Adaptation of fishes to the aquatic (water) habitat requires that they have the following:

- Scales, the hardened pigment that covers the skin of fishes and some other animals.

- Gills, the organ used by most fishes to breathe under water.

Other include tail, fin (dorsal, pelvic) etc. All these help the fish to adapt to the water environment.

answer; ///i believe the correct answer is (aids) acquired immune deficiency syndrome;

the answer will be a) proteins i believe