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Set 2: Central Ideas (Intermediate)

Explanation

Answer: B

PASSAGE

The following text describes Dark Matter. Dark matter is a hypothetical form of matter that is thought to account for approximately 85% of the matter in the universe. Unlike normal matter, dark matter does not appear to interact with the electromagnetic force; that is, it does not absorb, reflect, or emit light, making it extremely difficult to detect. Astronomers infer its existence from the gravitational effect it seems to have on visible matter, such as the rotation speeds of galaxies.

Why is dark matter difficult to detect directly?

A. It is located only in the most distant parts of the universe
B. It interacts too strongly with gravity to be seen✓ Correct
C. It does not interact with light or the electromagnetic force
D. It is constantly changing form, making it unstable

Detailed Explanation

Choice C is correct. The text states it 'does not appear to interact with the electromagnetic force' and 'does not absorb, reflect, or emit light.'

Key Evidence:

• "does not appear to interact with the electromagnetic force"

• "does not absorb, reflect, or emit light"

Why others are wrong: A (Not mentioned), B (Inaccurate (gravity is how it IS inferred)), D (Not mentioned).

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