Whch of the following below is one reason why groundwater become polluted? a. pollutants mixed with water pass through permeable layers above the aquifer. b. factories dump their waste directly into aquifers. c. refuse infiltrates the water table when garbage is dumped. d. all of the above

What causes an unsaturated fatty acid to have a different shape than a saturated fatty acid? o a. unsaturated fatty acids have more hydrogen atoms. o b. unsaturated fatty acids have double carbon bonds. o c. unsaturated fatty acids have more nitrogen atoms. o d. unsaturated fatty acids have single carbon bonds.

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

What is the most appropriate method of gaining weight (muscle mass)