Mafic rocks are...
a. high in silica content
b. low in Fe & Mg content
c. high in Fe & Mg content
d. low in silica content

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