What determined the temperature, density, and ratio of hydrogen to helium of the universe soon after the Big Bang? A. the rate at which the universe expanded
B. the rate of nuclear fusion in the first stars
C. the density of the material the universe was expanding into
D. the timing of the transition from an opaque to a transparent universe

What did the first language sound like

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?

Which locations on the map are low-pressure areas? a b c d e