Select the choice that best completes the following sentence. simple machines a. cannot be combined to make compound machines. b. are tools that make work easier. c. reduce the amount of energy needed to do work. d. are made up of multiple moving parts.

The agent of mechanical weathering in which rock is worn away by the grinding action of other rock particles is call

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.