Which of the following statements about good experiments is TRUE? a) A good experiment must include all possible causal factors in one experimental group.
b) A good experiment must have an experimental group. A control group may be useful but is not critical.
c) A good experiment should include a potentially confounding factor in at least one group.
d) A good experiment includes replication by applying treatments to multiple experimental units

An adult who follows a 2000-kcal healthy u.s.-style eating pattern should consume ounce-equivalents from the protein foods group per day.

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

Explain how fossils scientists make discoveries about the lives of organisms and about how environments have changed over time. plz hurry up it time