ACT english practice test 14

DIRECTIONS: In the passages that follow, certain words and phrases are underlined and numbered. In the right-hand column, you will find alternatives for the underlined part. In most cases, you are to choose the one that best expresses the idea, makes the statement appropriate for standard written English, or is worded most consistently with the style and tone of the passage as a whole. If you think the original version is best, choose “NO CHANGE.” In some cases, you will find in the right-hand column a question about the underlined part. You are to choose the best answer to the question.

You will also find questions about a section of the passage, or about the passage as a whole. These questions do not refer to an underlined portion of the passage, but rather are identified by a number or numbers in a box.

For each question, choose the alternative you consider best and fill in the corresponding oval on your answer document. Read each passage through once before you begin to answer the questions that accompany it. For many of the questions, you must read several sentences beyond the question to determine the answer. Be sure that you have read far enough ahead each time you choose an alternative.

Black Holes—Astronomy's Great Mystery

Black holes are likely and possibly46 the most fascinating topic facing contemporary astronomy. The concept of a black hole—a region of space with such intense gravitational pull that nothing can escape—is truly the stuff of science fiction. That is what Albert Einstein believed, at least. His general theory of relativity predicted their existence, but he thought47 of his prediction as an error to be corrected, not a predictor of one of the strangest astronomical phenomena yet discovered.

Because48 Einstein didn't live to see it, the universe proved the accuracy of his calculations in 1970, when Cygnus X-1 was discovered about 7,000 light-years from Earth. It is about 8.7 times as massive as our Sun yet has a small49 diameter of only about 50 km. When you consider that the diameter of the Sun could accommodate over 100 Earths, it becomes clear that fitting a mass almost nine times greater than that into a space of about 31 miles is truly remarkable.

How do these singularities come into existence?51 There are52 several theories to explain the process. The most popular hypothesis suggests that black holes are fairly common and involving53 the disintegration of a massive star near54 the end of its lifecycle. At that stage, the star has nearly exhausted its hydrogen supply, consequently55 losing its ability to burn at a sufficiently high temperature to prevent its collapse. The stars exterior,56 layers are blown away in a supernova, while the interior layers collapse into a highly dense core, which ultimately becomes the black hole.

Other theorists suggesting57 that black holes are the result of a galactic game of bumper cars. The universe is teeming with neutron stars. These are highly compact, very hot stars formed during the supernova of smaller stars that are not sufficiently massive to create black holes. Likewise,58 on occasion these stars will actually collide with each other and together become massive enough to form a black hole.

Perhaps the most bizarre observation made about these phenomena involves the existence of "micro" or "mini" black holes. These peculiar items are very small, astronomically speaking. They have a mass far less than that of our Sun, and, frankly, the scientific community cannot explain and articulate fully59 how stars with so little mass could have formed black holes at all. That is a question for future generations of scientists to explore.


G. very probably to be
H. possibly
J. a possible likeness of being


B. thinks
C. have thought
D. has thought


G. Although
H. Since
J. DELETE the underlined portion.


B. less
C. fewer
D. too little

50. If the writer were to delete the preceding sentence, the paragraph would primarily lose:

F. a description that explains the purpose of studying black holes.
G. information that helps the reader grasp the size of black holes by presenting it in understandable terms.
H. a reference that explains how the black hole is compressed into such a small size.
J. an unnecessary detail, because this information is repeated later in the passage.

51. Which choice provides the most effective transition from the previous paragraph to the new paragraph?

B. Why should we study black holes at all?
C. Is the Sun going to collapse and become a black hole?
D. What are the effects of such massive gravitational pull?


G. Their are
H. Their is
J. They're are


B. is involving
C. will involve
D. involve

54. Which of the following alternatives to the underlined portion would NOT be acceptable?

F. close to
G. close
H. toward
J. around


B. supply; consequently
C. supply, and consequently
D. supply. Consequently


G. stars exterior
H. star's exterior
J. star's exterior,


B. has been suggesting
C. will suggest
D. suggest


G. Similarly,
H. However,
J. In addition,


B. cannot explain or describe in any detail
C. cannot explain
D. not only cannot explain but also can't describe

60. This question asks about the preceding passage as a whole.

Suppose the writer's goal had been to write a brief essay about how Einstein's skepticism stopped scientific inquiry into the existence of black holes. Would this essay successfully fulfill that goal?

F. Yes, because black holes were not discovered until after Einstein's death.
G. Yes, because no other scientists were mentioned by name as doing research into the subject.
H. No, because Einstein later decided that black holes did exist and encouraged the scientific community to search for them.
J. No, because no discussion is made of how Einstein's doubt affected the inquiries of other scientists.