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MCQBeginnerCosmology & Galaxies
IAAC — 2025 Final Round
Question 20
The question of why the night sky is dark despite the vast number of stars is known as ...
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Source
Source: International Astronomy and Astrophysics Competition (IAAC), Final Round 2025. Question wording and answer-choice text are transcribed from the official training PDF; the explanation and metadata are original.