Set 3: Text Structure

Explanation

Answer: A

PASSAGE

Penguins are birds, but they cannot fly. Instead, they use their wings as flippers. This allows them to swim very fast underwater to catch fish.

Which choice best describes the function of the underlined sentence?

A. It explains a unique adaptation of penguins.✓ Correct

B. It argues that penguins should not be called birds.

C. It describes the color of penguin feathers.

D. It lists the fish penguins like to eat.

Detailed Explanation

Using wings as flippers instead of for flying is an adaptation. The sentence explains what they do 'Instead'.

Key Evidence:

• "use their wings as flippers"

Why others are wrong: B (First sentence states they are birds.), C (Color not mentioned.), D (Fish type not listed.).