Ascientist plans to find out if dams harm a river ecosystem. he interviews 500 enviormentalists and 450 of them believe dams are harmful to the ecosystem. the scientists concludethat 90 percent of people believe that dams are harmful. why is the scientist's comclusion most likely unrealible.

Environmental impacts on evolution : mastery test

Sally and sue were investigating the topic of friction in science. they used a small car and a ramp as seen in the picture to test what they were learning. they knew that they slipped easily on waxed floors but not on carpet, so they decided to change the material on the surface of the ramp to see what happened. they planned to use glass, carpet, aluminum foil, and sandpaper and run the car down the ramp over each surface. what would be the best research question to guide the girls' experiment? a) does the amount of surface area affect the friction on the moving car? b) will the car travel fastest on the glass surface? c) how does the angle of the ramp affect the speed of the car? d)do rougher surfaces tend to create more friction than smooth surfaces?

Choose the diagram that best represents a habitat corridor explain your choice.