Dolphins instinctively swim from electrical fields
A
In the wild, dolphins sometimes encounter strong electric fields.
B
Vibrissal crypts enable dolphins to sense electric fields.
C
Dolphins do not instinctually avoid electric fields, but they can be trained to do so.
D
Electric fields interfere with the normal functioning of dolphins’ vibrissal crypts.
E
Under normal circumstances, dolphins are unable to sense electric fields.
A
When they are at home, laborers and office workers tend to spend similar amounts of time sitting.
B
Insurance companies tend to dislike selling policies to companies whose workers often claim to have back pain.
C
People who regularly do physical work of a type known to place heavy stress on the lower back are encouraged to use techniques that reduce the degree of stress involved.
D
Most of the lower-back injuries that office workers suffer occur while they are on the job.
E
Consistent physical exercise is one of the most effective ways to prevent or recover from lower-back injuries.
An analysis of the language in social media messages posted via the Internet determined that, on average, the use of words associated with positive moods is common in the morning, decreases gradually to a low point midafternoon, and then increases sharply throughout the evening. This shows that a person’s mood typically starts out happy in the morning, declines during the day, and improves in the evening.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that a person’s mood usually starts out happy in the morning, drops during the day, and improves in the evening. He supports this by citing a study of the language used on social media, which found that words linked to positive moods are common in the morning, decrease in the afternoon, and rise again in the evening.
Identify and Describe Flaw
The author makes two main assumptions. First, he assumes that social media language accurately reflects a person's mood. But someone could be unhappy in the morning and still post a happy message, or vice versa.
Second, he assumes that the analysis followed the same individuals throughout the day. If people who post in the morning are different from those who post in the afternoon or evening, he can't conclude that a person's mood follows the same pattern as the language used on social media.
A
people’s overall moods are lowest at the beginning of the workweek and rise later, peaking on the weekend
The author’s argument and the analysis that he cites are both only about a person’s mood throughout a single day. The pattern of people’s moods throughout the whole week is irrelevant.
B
many people who post social media messages use neither words associated with positive moods nor words associated with negative moods
The author’s evidence only looks at those people who do use words associated with positive or negative moods on social media. The fact that many people don’t use these words is irrelevant.
C
the frequency in the use of words in social media is not necessarily indicative of the frequency of the use of those words in other forms of communication
The use of mood words in other forms of communication is irrelevant; the author only addresses language on social media. He does overlook the possibility that social media language isn’t necessarily indicative of people’s actual moods, but this is not what (C) points out.
D
the number of social media messages posted in the morning is not significantly different from the number posted in the evening
The author doesn’t overlook this possibility. He’s focused on the frequency of positive mood words used in social media messages, not the number of messages posted at different times of the day.
E
most of the social media messages posted in the evening are posted by people who rarely post such messages in the morning
If most evening messages are posted by different people than the morning messages, the author can't conclude that a person's mood follows the same pattern as the messages. The messages came from different people— this tells us nothing about one person’s mood throughout the day.
forage
Verb. 1. (of a person or animal) search widely for food or provisions.
"gulls are equipped by nature to forage for food"
source