What are the classes of crayfish, crabs, scorpions, lobsters?

Which of the following is an oxidation-reduction reaction? (pictured below)

In some plants, pointed leaves (p) are dominant over rounded leaves (p). a plant with a genotype of pp

Which short-term environmental changes would a very small asteroid or comet impact on earth most likely cause? check all that apply. flooding extinction craters on surface changes in weather patterns death of organisms and populations