Scientists generally agree that earth is getting warmer due to what's called the greenhouse effect. (2) a greenhouse stays warm because sunlight and heat coming through the glass roof are mostly trapped. (3) the heat doesn't radiate back into the atmosphere because it's held in by the glass. (4) something like that happens on earth. (5) the atmosphere acts like a blanket that keeps the sun's heat from leaking away into space.

which sentence is the paragraph's topic sentence?

Read this excerpt from the narrative of the life of frederick douglass. the more i read, the more i was led to abhor and detest my enslavers. . i loathed them as being the meanest as well as the most wicked of men. as i read and contemplated the subject, behold! that very discontentment which master hugh had predicted would follow my learning to read had already come, to torment and sting my soul to unutterable anguish. which statement best describes douglass's viewpoint? he believes that increased knowledge inspires a greater hatred of injustice. he believes that master hugh deeply regrets his harsh treatment and seeks to stop. he believes that master hugh’s cruel treatment is severely injuring his well-being. he believes that the material he reads is upsetting to him and master hugh.

Which scenario describes intraspecific, indirect competition? a. a peacock defends its territory against another peacock. b. lions and hyenas compete for the same prey animals. c. a male black bear eats fish in an area of a lake, so other black bears can’t. d. different species of birds fight over spilled popcorn on the ground.

An ecosystem is shown in the illustration. assume that human activities have led to a decrease in the number of eagles. a virus attack on rabbits has led to a decrease in their population in the ecosystem. which two sentences describe likely effects on the ecosystem? 1. there’s an increase in the number of snakes and insects and a decrease in the number of frogs. 2. there’s an increase in the number of snakes and insects, and the storks face increased competition for food. 3. there’s an increase in the number of storks and a decrease in the number of snakes and insects. 4. there’s an increase in the number of frogs and a decrease in the number of storks and insects. 5. there’s a decrease in the number of snakes, insects, and frogs.