Enzymes can be denatured (unfolded) by what environmental factors?

When analyzing tree rings, what do scientists assume a thin ring indicates?

What type of pollution does household garbage cause

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