ACT reading practice test 50

DIRECTIONS: Each passage is followed by several questions. After reading a passage, choose the best answer to each question and fill in the corresponding oval on your answer document. You may refer to the passages as often as necessary.


Natural Science

This passage is adapted from "The Creepy Scientific Explanation Behind Ghost Sightings" by Jack Mendoza, which appeared on cracked.com (October, 2010).

There is simply no evidence that dead people wander aimlessly around old houses, and no known scientific principle that would make it possible, but a lot of people have seen ghosts. There are certain spots and

5 buildings where separate, unrelated witnesses have reported ghosts, without having talked to each other or being aware of the area being "haunted."

It appears that science has stumbled across the reason for it. It has nothing to do with the supernatural, but

10 the answer is almost as weird. While working in his robotics laboratory, Vladimir Gavreau noticed that one of his assistants was bleeding from the ears. Puzzled, Gavreau started researching the phenomenon, and soon realized that a vibrating pipe of the right length and girth

15 can cause a number of unpleasant effects ranging from mild irritation to serious pain.

What he had discovered was infrasound. It's noise at a low enough frequency that you don't consciously hear it, but your ears still sense it. The process of receiving

20 sensory input without your conscious mind understanding where it's coming from wreaks havoc with your emotions. Specifically, researchers found that sounds between 7 and 19 Hz could induce fear, dread or panic.

As an experiment, acoustic scientists sneaked

25 in low-frequency sounds at a live concert. Most of the concertgoers had no idea what was going on. At the end of the experiment, 22 percent of the people involved reported feelings of unexplainable dread, chills and depression when infrasound was blasted into the crowd.

30 "Why would it have this effect It may be evolution. It doesn't take a mad-scientist device to create infrasound: nature creates this type of low-frequency vibration all the time. Volcanos, earthquakes, strong ocean waves and even winds hitting the hillside in just the

35 right spot can create infrasound. Even animals can create it. The frequency of a tiger's roar is around 18 Hz. All the things that create the sound are huge, powerful and dangerous. Evolution might have taught us that this sound means bad news.

40 "So now we have a phenomenon that occurs in nature, is invisible, is imperceptible on a conscious level, but can spontaneously make you feel irrational fear, even if you're sitting in an empty room. We've just described one of the first and primary signs of a

45 "haunting"-unexplained feelings of fear or dread. But what about actual sightings of ghosts For that we need to go to a researcher named Vic Tandy. In the engineering building where Tandy worked, cleaning staff as well as fellow researchers complained of feeling dread, depression

50 and a strange feeling that someone was watching them. Every so often, the staff would see dark figures out of the corners of their eyes. After one particularly strange experience when a gray shape sat next to his desk for several minutes, Tandy was determined to figure out

55 what was going on. After eliminating gas poisoning and rogue equipment, he realized that the ghostly apparitions seemed to almost always occur in a certain section of the lab. He also realized that if he put a metal sheet in a vice, it would spontaneously vibrate uncontrollably for no

60 apparent reason.

Poltergeist No, just infrasound. A silent exhaust fan was sending out low-frequency vibrations that bounced back and forth on the lab's walls until they formed a powerful wave at 18.9 Hz, right at the top of the panic

65 range. According to a NASA study, it was powerful enough to resonate with the average human eyeball, causing "smeared" vision, a phenomenon where the eye vibrates just enough to register something static-say, the frame of your glasses or a speck of dust-as large,

70 moving shapes. Once the fan was removed, the strange apparitions and feelings of fear disappeared.

Convinced that he had stumbled onto something, Tandy went on to test this explanation for ghostly apparitions in the cellar of a nearby "haunted" abbey.

75 According to the locals, as soon as someone would step into the cellar they would freeze up, see strange gray ghosts and have to leave because of nausea. Vic discovered that the shape of the cellar and the hallway leading to it, as well as nearby factories, all contributed to making

80 the haunted cellar a perfect resonating chamber. The vibrations created were exactly 18.9 Hz and were most powerful at the threshold of the cellar, where most people became sick and terrified.

So if you're ever troubled by strange noises in the

85 middle of the night or you experience feelings of dread in your basement or attic or even if someone in your family sees a ghost…. Well, call the repair guy, because it might be caused by a malfunctioning ventilation fan.

1. The primary purpose of the passage is to:

A. suggest that the vast majority of ghost sightings have in fact been elaborate hoaxes.
B. explain why legends about supernatural experiences have gotten more numerous as technology advanced.
C. suggest that the myth of haunted houses is caused by an explainable phenomenon.
D. gently satirize the types of people who claim to have seen ghosts or believe in hauntings.

2. The main function of the fifth paragraph (lines 30-39) in relation to the passage as a whole is to:

F. explain that most people who reported supernatural experiences were probably actually hearing animals.
G. suggest that virtually anyone could successfully fake a haunting without a lot of elaborate equipment.
H. argue in favor of belief in evolution over belief in supernatural things like ghosts.
J. explain why humans would have evolved the responses that cause them to imagine ghosts.

3. The author uses the story of the concert experiment (lines 24-29) primarily to demonstrate that:

A. the feelings normally reported in conjunction with a haunting are replicable even in people who are not expecting to feel them.
B. the percentage of people who respond to infrasound goes down when they are exposed to it in large groups.
C. many reported supernatural experiences are probably the result of elaborate pranks.
D. the scientists who developed the infrasound theory of hauntings were irresponsible, and therefore further study is needed.

4. The scientific theories described in the passage would appear to explain all of the phenomena traditionally associated with ghosts and haunting EXCEPT:

F. sudden feelings of unease or panic.
G. information supposedly communicated by ghosts.
H. personal injury supposedly inflicted by ghosts.
J. distinct, moving visual apparitions.

5. According to the author, it's entirely possible that most of the people in history who reported seeing ghosts were actually:

A. making an honest mistake.
B. unusually superstitious, even for their time.
C. inventing stories to explain their inexplicable emotions.
D. knowledgeable about science.

6. According to the passage, apparent ghost sightings are most likely to be the result of a (an):

F. animal's roar at 14 Hz.
G. powerful wind vibrating at 7 Hz.
H. ventilation fan vibrating at 12 Hz.
J. broken refrigerator vibrating at 18 Hz.

7. As it is used in line 21, havoc most nearly means:

A. depression.
B. chaos.
C. misunderstanding.
D. surprise.

8. In the context of the passage, the phrase "bad news" most nearly represents something:

F. liable to cause depression and sadness.
G. incomprehensible to the human mind.
H. real and potentially dangerous.
J. imaginary and potentially frightening.

9. The passage indicates that Vladimir Gavreau was initially motivated by a desire to:

A. discover infrasound.
B. find a scientific explanation for ghost sightings.
C. investigate a specific physical ailment.
D. make his work with robotics more efficient.

10. Suppose a group of researchers wanted to construct a haunted house. They would most likely need to make use of:

F. a device sending out vibrations at a certain frequency.
G. live animals.
H. rooms of a precise, predetermined shape.
J. both F and H.