Blood is a mixture of a variety of materials. Some of the materials are dissolved in the fluid portion of blood. Other materials, such as blood cells, do not dissolve but move along with the blood.

Where is having brightly colored feathers that attract mates most clearly an adaptation for a bird? a. a forest with dense vegetation b. a sandy beach beside an ocean c. a snowy tundra with little vegetation d. a swamp with many hawks that eat birds