In the 1970s, staghorn corals dominated Caribbean reefs. Since that time, staghorn corals have declined by over 90% and are now classified as critically endangered. What do you think are the causes of this decline, and why do you think staghorns are so vulnerable?

2. if scientists identify an animal with bilateral symmetry and no segmentation, which phylum can it definitely not belong to? a. roundworms b. annelids c. mollusks d. flatworms

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

What are some natural processes that represent physical and chemical changes?