【推荐1】Do you ever notice how stress and mental frustration can affect your physical abilities? When you are worried about something at work, do you find yourself more tired at the end of the day? This phenomenon is a result of the activation of a specific area of the brain when we attempt to participate in both physical tasks and mental tasks simultaneously.

Ranjana Mehta, Ph.D., assistant professor at the Texas A&M Health Science Center School of Public Health, carried out a study examining the relationship between physical and mental tiredness and brain behavior. The study showed that if we attempt mental tasks while doing physical tasks, we activate specific areas, called the prefrontal cortex (PFC) (前额皮质), in our brain.

This can cause our bodies to become tired much sooner than if we were only participating in a physical task. The brain is just like any other biological tissue (组织), because it can be overused and can suffer from tiredness.

“Existing examinations of physical and mental tiredness have been used to study muscular and biomechanical (生物力学的) changes,” said Mehta. “The purpose of this study was to examine the influence on the PFC while we compare the changes in brain behavior with traditional measures of tiredness.”

According to Mehta, study findings show that there were lower blood oxygen levels in the PFC following combined physical and mental tiredness compared to that of just physical tiredness conditions. Through simultaneous examination of the brain and muscle function it is obvious that when we participant in highly cognitive tasks, brain resources are divided which may speed up the development of physical tiredness.

It is critical that researchers consider the brain as well as the body when examining tiredness development and its influence on the body. This can provide us with a total understanding of what is happening to the body when we perform our daily activities. “Not a lot of people see the value in looking at both the brain and the body together,” said Mehta. “However, no one does purely physical or mental work; they always do both.”

1. What does the passage mainly tell us?

A．Influence of stress and mental frustration on tiredness development.

B．Influence of stress and mental frustration on mental abilities.

C．Influence of mental work on tiredness development.

D．Influence of physical work on mental abilities.

2. What does the underlined word “simultaneously” in the first paragraph probably mean?

A．At the same time.

B．One by one.

C．Step by step.

D．Over and over again.

3. It can be inferred that Ranjana Mehta's study has little to do with________.

A．tiredness in the body	B．brain behavior
C．mental tiredness	D．mental diseases

4. The brain is not an exception in the body when it________.

A．is used to complete a specific task

B．suffers from tiredness caused by overuse

C．becomes tired much sooner

D．is examined from a physical view

5. According to Mehta, one of the study's aims was to find________.

A．how the combination of physical and mental tasks affects the PFC

B．the differences between brain behavior and traditional measures

C．why changes in brain behavior influence the PFC

D．muscular and biomechanical changes

【推荐3】Patients often come into my office and ask, “How can I look younger?” While I always suggest healthy living — a balanced diet and regular exercise — in order to look and feel younger, I have never thought of facial exercises as part of that plan. That is, until a recent study, published in JAMA Dermatology (皮肤学), showed promising results that routine facial exercise may slow the merciless tide of time.

The theory behind the study originates from the fact that a major part of facial aging is due to the loss of fat and soft tissue, which leads to the growth and spread of wrinkles. If we can lift weights at the gym and enlarge muscles in arms, why couldn’t the same be done for muscles in our faces, therefore to create a more youthful face?

The concept of facial exercise is not a new one. A simple Internet search will produce a lot of blog posts and books on the subject, as well as various programmes that promise to be the next fountain of youth. What the JAMA Dermatology researchers did in their study, which was the first of its kind, was to examine this question from a more strict scientific aspect. They enrolled 27 women between the ages of 40 and 65 to perform daily, 30-minute exercises for eight weeks, and then continue every other day for a total of 20 weeks.

Dermatologists who did not know the participants were asked to rate their photographs before and after the exercise. The dermatologists found an improvement in cheek fullness and estimated the age of the participants at 51 years of age at the start of the programme and 48 at the end of the 20-week study. Furthermore, all the participants felt improvement in their own facial appearance at the end of the study.

While these results seem exalting, the study has some obvious limitations. Of the 27 patients involved, 11 gave up before completing the study. One reason may be that the programme was to time-consuming, clocking in at 30 minutes a day. The overall small size of the study also limits its generalizability to the larger population. In addition, there was also no control group, which would have helped reduce the possibility that this improvement happened by chance.

It’s also hard to draw conclusions about the longevity of these results. Probably the exercises must be continued to keep their effects. But for how long? And how frequently? Which exercises are most effective? Most studies are need to answer these questions.

1. According to the passage, which statement is true?

A．Though the concept of facial exercise is new, much information about it can be found on the Internet.

B．Some participants did not feel improvement in their facial appearance at the end of the study.

C．If there is a control group, the possibility that the improvement in the facial appearance happened by chance will be increased.

D．The reason why some participants quit the study before it was completely may be that they had not enough time.

2. What does the underlined word exalting mean?

A．Calming.

B．Challenging.

C．Frustrating.

D．Exciting.

3. What is the author’s attitude towards the study published in JAMA Dermatology?

A．Doubtful.

B．Positive.

C．Opposed.

D．Indifferent (中立的).

4. What can be inferred from the passage?

A．The study published in JAMA Dermatology is not reliable.

B．Healthy living is the only way to make someone look and feel young.

C．More studies are needed to further the present study on facial exercises.

D．As a dermatologist, the author was involved in the research project on facial exercises.