Compared to optical telescopes, radio telescopes are built large because
A) radio waves have very long wavelengths.
B) radio waves are absorbed by the atmosphere.
C) atmospheric turbulence is more of a problem.
D) they're less expensive to make than optical telescopes.
E) radio sources are harder to find.
Question 2
Which three worlds have almost identical densities?
A) Mercury, Mars, and our Moon
B) Mercury, Venus, and Earth
C) Earth, Moon, and Mars
D) Mercury, Earth, and Mars
E) Deimos, Phobos, and our Moon
(a) Feeding by bear on salmon results in large allochthonous inputs of nutrients into (b) the forest
Evolution of the Sun's luminosity, radius and effective temperature compared to the present Sun
Urinometer. In this procedure, a urine sample and urinometer are placed within a tube, and the liqui
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Optical Illusion