Mr. grammarcy has been having trouble sleeping at night, and his lack of sleep is beginning to interfere with his ability to function properly during the day. he’s concerned that he may lose his job in the next round of lay-offs at his company. he is also having marital problems. he tends to lay awake at night, worrying about these problems and thinking about what he can do to resolve these issues. based on the discussion in the text, mr. grammarcy should understand that
a. worrying increases one's bodily arousal, which can prevent normal sleep
b. sleep is a natural function that cannot be forced without medical intervention or biofeedback training
c. daily hassles and concerns do not normally interfere with normal sleep, so he should look for a medical reason for his insomnia
d. sleeping pills, used according to directions, will resolve his sleep problems
e. when his marital issues are resolved, his sleep pattern will return to normal, regardless of his concerns about his job

It is widely assumed that people need to engage in intellectual activities such as solving crossword puzzles or mathematics problems in order to maintain mental sharpness as they age. in fact, however, simply talking to other people—that is, participating in social interaction, which engages many mental and perceptual skills—suffices. evidence to this effect comes from a study showing that the more social contact people report, the better their mental skills. which of the following, if true, most seriously weakens the force of the evidence cited? (a) as people grow older, they are often advised to keep exercising their physical and mental capacities in order to maintain or improve them. (b) many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation. (c) many people are proficient both in social interactions and in solving mathematical problems. (d) the study did not itself collect data but analyzed data bearing on the issue from prior studies. (e) the tasks evaluating mental sharpness for which data were compiled by the study were more akin to mathematics problems than to conversation.