Which of the following describes how biodiversity contributes to the sustainability of a natural environment?
a. logging allows for the collection of firewood in the mountains of southwest china.
b. non-native alligator weed forms dense mats that crowd native species in california.
c. mining in the guinean forests of west africa provides diamond and gold jewelry for humans.
d. giant kangaroo rats enrich the soil for plants with their piles of grass clippings in the california grasslands.

What happens to the velocity of the car when the upward pull of the cable is greater than the downward pull of gravity as the car rises toward the top?

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

Which configuration would produce an electric current? a) rotate a coil of copper wire between two magnets. b) connect a wire between a copper and zinc strip sitting in a beaker of water. c) connect a wire to the (+) positive end of a battery and the other end to a light bulb. d) connect a wire to the negative end of a battery and the other end to a light bulb.