Answer: the correct answer is (B) He did not know that interstellar dust made it hard from him to see a large part of the Milky Way's disk.
Explanation:
We live in a dusty Galaxy. Because interstellar dust absorbs the light from stars, Herschel could see only those stars within about 6000 light-years of the Sun.
The answer would be point A.
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3 is 3.81 meters
4 is 0.47 liters
5 is 4 cm
6 is 23 mm
7 is 53 m
8 is 1800 mg
9 is 31.07 mi
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