Scientists are studying the body’s _____ for controlling weight.

Sleep plays a major role in preparing the body for an alert and productive tomorrow. But sleep is not a period of inactivity. The sleeping brain is highly active at various times during the night, performing numerous "house keeping tasks". These keep us alive and aid our ability to think and remember. Sleep also energizes the body and brain. Most people spend one-third of their lives sleeping and this will affect the other two-thirds in terms of alertness, energy, moods, body weight, perception, memory, thinking, reaction time, productivity and performance.

To limit sleep means our health and daytime potential are significantly reduced. So, good sleep strategies are essential in order to feel energized day after day. There is no strategy which works for everyone, so each person needs to experiment. One important thing is that you shouldn't worry too much if you go a few nights without a lot of sleep. It won't ruin your life. On any given night, one in four people can't sleep properly and everyone suffers from a lack of sleep at some time.

How does one minimize this problem? It is really quite simple. The first thing you must do is to reduce stress as much as possible. Stress is part of everyday life and, while we can never be entirely without stress, it can be managed. This means taking control of your life and focusing on what is important. One sleeping strategy is to sit in a comfortable position, close your eyes and relax all your muscles, breathing easily through your nose. Continue this for ten to twenty minutes. This should help you reduce stress and sleep better. Or, you can try getting plenty of exercise, because a tired body is likely to sleep better.

According to the article, sleep is important because______.

A．it is a period of complete inactivity for the brain

B．it helps us understand what we have already achieved

C．it makes us more effective when we are awake

D．it helps us to lose weight

A bond portfolio manager is considering three Bonds – A, B, and C – for his portfolio. Bond A allows the issuer to call the bond before stated maturity, Bond B allows the investor to put the bond back to the issuer before stated maturity, and Bond C contains no embedded options. The bonds are otherwise identical. The manager tells his assistant, “Bond A and Bond B should have larger nominal yield spreads to a U.S. Treasury than Bond C to compensate for their embedded options.” Is the manager most likely correct?

A. Yes.

B. No, Bond A’s nominal yield spread should be less than Bond C’s.

C. No, Bond B’s nominal yield spread should be less than Bond C’s.

TEXT B

Considering that anxiety makes your palms sweat, your heart race, and your brain seize up like a car with a busted transmission, it's no wonder people reach for the Xanax to vanquish it. But in a surlmse, re- searchers who study emotion regulation-how we cope, or fail to cope, with the daily swirl of feelings-are discovering that many anxious people are bound and determined (though not always consciously) to cultivate anxiety. The reason, studies suggest, is that for some people anxiety boosts cognitive performance.

In one recent study, psychologist Maya Tamir of Hebrew University in Jerusalem gave 47 undergraduates a standard test of neuroticism, which asks people if they agree with such statements as "I get stressed out easily." She then presented the volunteers with a list of tasks, either difficult (giving a speech, taking a test) or easy (washing dishes), and asked which emotion they would prefer to be feeling before each. The more neurotic subjects were significantly more likely to choose feeling worried before a demanding task; non-neurotic subjects chose other emotions. Apparently, the neurotics had a good reason to opt for anxiety: when Tamir gave everyone anagrams to solve, the neurotics who had just written about an event that had caused them anxiety did better than neurotics who had recalled a happier memory. Among non-neurotics, putting themselves in an anxious frame. of mind had no effect on performance.

In other people, anxiety is not about usefulness but familiarity, finds psychology researcher Brett Ford of the University of Denver. She measured the "trait emotions" (feelings people tend to have most of the time) of 139 undergraduates, using a questionnaire that lists emotions and asks "to what extent you feel this way in general." She then grouped the students into those characterized by "trait fear" (those who tended to be anxious, worried, or nervous), "trait anger" (chronically angry, irritated, or annoyed), and "trait happy" (the cheerful, joyful gang). Six months later, the volunteers returned to Ford's lab. This time she gave them a list of emotions and asked which they wanted to experience. Not surprisingly, the cheerful bunch wanted to be happy. But in a shock for those who think anyone who is chronically anxious can't wait to get thek hands on some Ativan (氯羟安定), those with "trait fear" said they wanted to be worried and nervous-even though it felt subjectively unpleasant. (The "trait angry" students tended to prefer feeling the same way, too.) Wanting to feel an emotion is not the same thing as enjoying that emotion, points out neuroscientist Kent Berridge of the University of Michigan, who discovered that wanting and liking aremediated by two distinct sets of neurotransmitters.

In some cases, the need to experience anxiety can lead to a state that looks very much like addiction to anxiety. "There are people who have extreme agitation, but they can't understand why," says psychiatrist Harris Stratyner of Mount Sinai School of Medicine in New York. They therefore latch on to any cause to explain what they're feeling. That rationalization doubles back and exacerbates the anxiety. "Some people,"

he adds, "get addicted to feeling anxious because that's the state that they've always known. If they feel a sense of calm, they get bored; they feel empty inside. They want to feel anxious." Notice he didn't say "like. "

The studies of emotion regulation suggest that

[A] anxiety can cause palms to sweat and hearts to race.

[B] anxiety can be vanquished by Xanax.

[C] anxious people tend to feel uncomfortable.

[D] anxiety can enhance cognitive competence.

If three bonds are otherwise identical, the one exhibiting the highest level of positive convexity ismost likely the one that is:

A. option-free

B. callable

C. putable

_____ experiencing the booms and busts of old, the economy is on a steady growth.

A、Other than

B、 Rather than

C、 No more than

D、 No other than

When the corporation issuing the bonds has the right to repurchase the bonds prior to the maturity date for a specific price, the bonds are

A. convertible bonds

B. unsecured bonds

C. debenture bonds

D. callable bonds