Which of these is an advantage of hydroelectric energy? a. is expensive to build or maintain b. reduces greenhouse gas emissions c. harms aquatic organisms d. is available only in limited areas

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels

Analyze how the water cycle affects a food web. now list 3 examples for each below using complete sentences, on how too much water would affect the same web? how about to little water?

Which tool could you see a plant cell? a. a filter b. a microscope c. a microwave d. an electromagnet