The unmodulated carrier wave is going into the box, and when it comes out, its AMPLITUDE has been modulated.
You can eliminate the answer A because the moon is super cold
For answer B, atmosphere is contained of gasses, not just oxygen alone
Definitely not C
The answer is D because the moon's gravity isn't strong enough to hold the gasses, as a result, only a small amount of gasses has an attraction to it ( the moon has a little atmosphere though) but not enough to be considered
A geologist is studying rock layers in an old river bed, and he finds a fossil of a fish and a horsetail rush in the same rock layer. According to the law of faunal and floral succession, the geologist can assume that the rock containing the fossils may date back as far as the <span>Devonian period</span>.
