Multiple Choice
An HII region is
A) a zone around a hot star where hydrogen atoms are ionized
B) a place where there is mostly neutral hydrogen whose spectral lines we observe
C) a cloud of dark dust, which absorbs much of the starlight coming from behind it
D) one of the large and cold molecular clouds where we see star formation going on
E) a cloud of complex molecules, such as alcohol and formaldehyde
Correct Answer:
Verified
Correct Answer:
Verified
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