Which of the following explains the process of nitrogen fixation? A. converting ammonium into steroids for plants B. converting free nitrogen into ammonium
C. converting bacteria into nitrogen

If you have a difficult time knowing where your hand is without looking at it you may be having a problem with your what ?

Transmission electron microscope are best for viewing a) microorganisms in pond water b) internal organs of a mouse c)internal structures of a cell d) surface features of a specimen

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?