1 . One of the biggest causes of back injury at work is lifting or handling objects incorrectly, and many people have ever experienced such cases now and then while dealing with heavy objects.     1    

Think before you lift Plan the lift.     2     Where is the load (负载) going to be placed?Are the obstacles (障碍物) such as deserted outer packing in your way? For long lifts, such as from floor to shoulder height, consider resting the load mid-way on a table or bench to change your hold on it.

Keep the load close to the waist   Keep the load close to the waist for as long as possible while lifting to reduce the amount of pressure on the back.     3    If closely approaching the load isn’t possible, try to slide it towards the body before trying to lift it.

Adopt a stable position Your feet should be apart with one leg slightly forward to keep balance.     4    Wearing over-tight clothing or unsuitable footwear, such as high heels, may make this difficult.

    5     Don’t lift or handle more than you can easily manage. There’s a difference between what people can lift and what they can safely lift. If you’re in doubt, seek advice or get help.

A．Know your limits.

B．Will help be needed with the load?

C．Why not ask someone else to help?

D．Recognize your strengths and weaknesses.

E．Keep the heaviest side of the load next to the body.

F．Learning some correct methods can help prevent injury or a back pain.

G．Be prepared to move your feet during the lift to maintain a stable position.

2 . It is reported that the sense of smell plays a dominant role in the social interactions of all land animals except humans. Then the question arises: Is this because humans don’t use their noses in social settings the way all other land animals do? Or is this behavior covert (隐蔽的), rather than overt, in humans?

In fact, this is exactly what Inbal Ravreby, a graduate student in Prof. Noam Sobel’s laboratory in Weizmann’s Brain Sciences Department, tried to answer. And as several lines of evidence suggest that humans are constantly, although mostly subconsciously, sniffing themselves and others, Ravreby supposed that the latter is the case.

To test her hypothesis, Ravreby conducted the study with pairs of click friends: same-sex nonromantic friends whose friendships had originally formed very rapidly. Because such friendships emerge prior to an in-depth acquaintance, they may be particularly influenced by physiological characteristics such as body smell. She then collected body smell samples from these click friends and conducted two sets of experiments to compare the samples with those collected from random pairs of individuals. In one set of experiments, she performed the comparison with a device known as an electronic nose, or eNose, which assessed the chemical signatures of the smells. In the other, she asked volunteers to smell the two groups of body smell samples in order to assess similarities measured by human perception. In both types of experiments, click friends were found to smell significantly more like each other than the individuals in the random pairs.

Next, to rule out the possibility that body smell similarity was a consequence of click friendships, rather than a contributing cause, Ravreby performed an additional set of experiments, in which she used the eNose to “smell” a number of volunteers who were complete strangers to one another, and then asked them to engage in nonverbal (非言语的) social interactions in pairs. After each such structured interaction, the participants rated the other individual in terms of how much they liked that person. Subsequent analysis revealed that the individuals who had more positive interactions indeed smelled more like each other, as determined by the eNose.

“These results imply that, as the saying goes, there is chemistry in social chemistry,” Ravreby concludes. However, Sobel offers words of caution, “This is not to say that we act like dogs or goats — humans likely rely on other, far more dominant signals in their social decision-making. Nevertheless, our study’s results do suggest that our nose plays a bigger role than previously thought in our choice of friends.”

1. What did Inbal Ravreby want to figure out?

A．Whether humans have a sharp sense of smell.

B．Whether humans’ noses can detect all types of smells.

C．Whether it is necessary for humans to sniff other people.

D．Whether the sense of smell plays a role in humans’ interaction.

2. What makes the first two sets of experiments different from each other?

A．The way to make comparisons.	B．The participation of random pairs.
C．The way volunteers used the eNose.	D．The number of pairs of click friends.

3. Why did Ravreby involve complete strangers in the following experiments?

A．To determine the reliability of the finding.

B．To avoid interactions between click friends.

C．To make the experiments much more interesting.

D．To test the accuracy of the eNose in smell analysis.

4. What is Sobel’s attitude towards the research finding?

A．Disapproving.	B．Doubtful.
C．Positive.	D．Indifferent.

3 . Perhaps you use your headphones to enjoy music and peace and quiet during the day. But you may be neglecting the dangers of hearing loss with headphones.     1     This is 30% higher than just 20 years before, and experts are pinning it on headphones.

In fact, headphones are not a bad thing. They can bring peace, allow for better musical enjoyment, and even protect your ears from higher decibels(分贝).     2    

How long should you wear your headphones every day? The answer is, according to the World Health Organization, one hour per day.     3     But the fact is that the longer you listen, you’re going to lose your hearing sooner. To keep hearing loss from happening to you, you should follow the recommendation in place by the WHO that you keep your time with headphones on limited to one hour per day.

Then, how do you set the safest volume for your headphones? With headphones, it depends on the type you’re using and your environment. To test things out, you should take them off your ears and extend them in your hands out in front of you.     4     If you are using open-back headphones, you should try to have a conversation with someone nearby. When you’re able to carry on the conversation clearly, you’re listening at a proper volume. But do remember that never raise the volume on your listening device over 60% of the maximum!

    5     At others this loss will build up over time. It usually isn’t noticeable in the beginning. It’s not until it’s too late that most people realize that the damage has been done. The only way to know for sure is to consult your doctor.

A．This might seem unreasonable to you.

B．At times, hearing loss isn’t permanent.

C．l in 5 teens will have some types of hearing loss.

D．What’s more concerning is what that means for children.

E．It’s the duration and volume that cause the problem, however.

F．If you still hear your music clearly, you need to turn them down.

G．It’s a wonderful thing to shut out the rest of the world and enjoy your music.