Page 133 - READING COMPANION TO ENGLISH EXAMS

Answer the questions 27–29 according to the
passage below.

Black holes are mysterious cosmic objects 28. It is pointed out in the passage that black
formed from the remnants of massive stars or holes are considered invisible because ----.
through other means. They have such strong A) they do not emit any form of light or radiation,
gravitational fields that nothing, not even light, can making them impossible to detect
escape their gravitational pull once it crosses a
boundary known as the event horizon. There are B) their gravitation is not enough to make any
three primary types of black holes: stellar-mass noticeable changes in nearby objects
black holes, formed from massive star collapses; C) they reflect light, and observing them
intermediate-mass black holes, less common and is extremely difficult, even for proficient
with intermediate mass ranges; and supermassive physicists
black holes, residing at the centres of galaxies and
ranging from millions to billions of solar masses. D) their existence is inferred from the motion of
One of the most significant theoretical predictions nearby stars or gas and X-ray emissions
about black holes is that they can emit a type of E) they have such a strong gravitational pull
radiation due to quantum effects near the event that nothing, not even light, can escape from
horizon. Over extremely long timescales, this them
radiation can lead to the evaporation of black
holes. Actually, black holes are not black; they
are invisible, but their presence can be inferred
by their gravitational effects on nearby objects.
Astronomers detect them by observing the motion
of nearby stars or gas, as well as by detecting
X-rays emitted by matter falling into them.
However, there are still a lot of paradoxes to be
resolved, where the laws of physics break down
and pose a significant challenge to theoretical
physicists.

27. According to the passage, the primary factor 29. Which could be understood from the
that determines the type of black hole is the passage?
----.
A) Explaining black holes is an ongoing process
A) formation of the event horizon which includes many unexplained paradoxes.
B) amount of visible light emitted by it B) The primary challenge in studying black
holes is their unpredictable gravitational
C) gravitational pull of nearby stars
behaviour.
D) radiation leading to its evaporation
C) As they are invisible, black holes can only
E) mass of the collapsing star or object be studied through the theoretical laws of
physics.
D) Black holes are well understood, and there is
no significant development in their study.
E) The size and mass of black holes vary
independently, but they all have similar mass
ranges.

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