Which question is answered by the paragraph?
Read this paragraph by the National Aeronautics and
Space Administration (NASA) about black holes.
Don't let the name fool you: A black hole is anything but
empty space. Rather, it is a great amount of matter
packed into a very small area - think of a star ten times
more massive than the Sun squeezed into a sphere
approximately the diameter of New York City. The result
is a gravitational field so powerful that nothing, not even
light, can escape. In recent years, NASA instruments
have painted a new picture of these strange objects
that are, to many, the most fascinating objects in space.
O Which NASA instruments are used to study black
holes?
O How much light exists inside black holes?
How strong is the gravity force of black holes?
O How large in diameter are most black holes?
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