The speed of light in four different materials is shown below:

material speed of light in thousand miles per second
a 140
b 78
c 186
d 124

which material is the most dense?
material a
material b
material c
material d

Drag each description to the correct location on the image. not all descriptions will be used. describe the parts of a comet. the frozen part of the comet the atmosphere of gases and dust formed when the nucleus vaporizes tail made of small, solid dust particles tail made of ions that appears to point away from the comet's orbit

On a backpacking trip, kenny hikes all day at a steady pace, covering 30 kilometers and burning 4000 calories. at the school track, janelle runs the 100-meter sprint in 13.5 seconds, burning 10 calories. afterward, janelle’s leg muscles are aching and she is breathing hard, while kenny maintains normal breathing all day, even though he burns 400 times more calories than janelle. which two statements offer the best explanation for this phenomenon? a. if the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt." b. aerobic cellular respiration produces more energy, but its use is limited because of lactic acid buildup in the muscles and the resulting "oxygen debt." c. after about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce atp, resulting in "oxygen debt." d. the rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.

Aspecies has evolved an asexual mode of reproduction by having offspring develop from unfertilized eggs. which of the following will be true of this species' response to natural selection? there will be more deaths from natural selection because there is no mutation. there will be less genetic variation from recombination and a risk of not adapting quickly to environmental change. the species will increase in numbers because genetic variation is increased. the species will compensate for loss of genetic variation by hybridizing with other species. there will be fewer deaths from natural selection because sexual recombination always leads to extinction.