Psychologists(心理学家) are interested in the reasons why some people like taking part in risky sports.

When they studied people who were learning to jump from a plane with a parachute, they found that the parachutists’ bodies produced large amounts of two hormones(激素), adrenaline(肾上腺素) and noradrenaline(去甲肾上腺素), just before they made their jump. These hormones help to prepare us for any sudden activity. Adrenaline increases the heart beat and provides more sugar for the muscles(肌肉), while noradrenaline makes us react(反应) more quickly. However, noradrenaline also supplies energy to a part of the brain which controls feelings of pleasure. A feeling of pleasure caused by this hormone makes certain people want to take part in dangerous sports.

Another possible reason is the level of excitement in part of the brain. According to some psychologists, the brain tries to manage a certain level of excitement. They believe that people who have a low level of excitement look for new experiences in order to fire themselves with excitement, but people who usually have a high level of excitement try to avoid risks in order not to become overexcited. If the psychologists are right, people with a low excitement level are the ones who enjoy taking part in dangerous sports and activities.

It is thought that people with low levels of excitement have a slower-reacting nervous system than people with higher levels. So it may be possible to find out your level of excitement by testing your nervous system. A quick way of doing this is to put some lemon juice on your tongue(舌头). If you produce a lot of saliva(唾液), your nervous system has been affected(影响) by the lemon and so you probably have a high level of excitement; if you produce little saliva, you probably have a low excitement level. If you have a low level, you might enjoy taking part in risky sports. However, this does not mean that you have to try parachuting!

【推荐3】The human brain weights about 1.4 kilograms, but it can hold much more information than most computers. However, there is another difference between humans and computers. Computers don’t forget information they are given, and luckily we don’t usually have to. But everyone can improve their memory if they want to. Here are some suggestions.

Try to use new information right away. For example, if you meet someone who says “Hi! I’m Carlos,” don’t just say “Hello.” Repeat the person’s name. say “Hello”

Break a big number into smaller parts. For example, it’s hard to memorize 109244153, but if you divide it into three parts—109/244/153—it becomes easier.

Go over information. If you bring what you’ve learned back to your mind, they become easier to remember. For example, before you go to sleep, it’s a good idea to think about the new things you learned that day.

Never tell yourself that you have a poor memory. You can always do something to help improve your memory. And everyone’s memory gets better if they use it often enough.

All of the suggestions are helpful. If you follow them, you are certain to improve your memory.

【推荐1】To communicate with others well, we’d better build a better vocabulary. In our personal life, we communicate and share experiences with others. However, how to do it well depends on our ability to express ourselves through spoken and written language. Luckily, increasing our word power can make our ability better and can also help us in our study.

When you see a new word, just be ready to take out your dictionary and look it up-learn about the word and anything that relates (与……相关) to it. If you understand the word, you’ll hopefully remember it well.

Meanwhile, you’d better write down words to learn. You can look through the dictionary, magazine and newspaper, write down the words that you don’t know. Try to go over them every day-look at the words and speak them out loudly. Copy the words over and over again, along with their meanings, and you will surprisingly remember them in no time.

You can also do word games, such as word searches, crossword puzzles and so on. Playing these games, you may come across new words, and when you don’t know the words, study them. The more words you have in your brain's word bank, the better you will become at these word games. You will be remembering, learning and having fun, too.

Finally, reading is also an excellent way to learn new words and build up your vocabulary. Read things you are interested in, but don’t skip over (忽略) those words you don’t know. Instead, you should remember and use them in your own daily conversations. Use them more, and you'll surely have a better chance of remembering them.

【推荐3】Stress can be a silent killer, and can cause a lot of health problems, like being fat, heart disease and sleep problems. In last week’s free chat, we asked our readers how they get rid of it during their busiest times.

Forget your worries

@Tina

For me, the best way to relax is to watch comedy (喜剧), which brings lots of fun. After watching and laughing aloud, I forget all my worries!

@Jane

When I’m unhappy or sad I like listening to music and going to bed early. Music has magic that lifts my spirits and getting a good night’s sleep helps me forget my stress. I tell myself: tomorrow will be wonderful.

Recharge with exercise

@Shaw

The first year after I graduated, I worked as a translator, mainly responsible for translating all kinds of materials. I wanted to show not only my boss but also the whole world what I could do.

I asked for much more tasks than I could really do, which made me so stressed every single day. I didn’t know how to solve my troubles. Thanks to team building exercises we organized every month, I decided to follow my boss and become a marathon runner.

@Diner

As an English teacher since 1981, whenever I find myself under pressure, I choose to walk around the campus, listening to the BBC and VOA, which never fails to make me feel better.

Keep working under pressure

@Clean

As a final-year university student, I am not busy preparing for final exams as I have taken most courses in the first three years.

Some may think I’m fortunate, but the truth is that I really miss the busy days gaining knowledge, taking exams, getting good grades, and winning prizes. I believe real happiness comes when one is busy.

@Chips

With winter holidays drawing near, I feel stressed as a teacher in senior school. Making to-do lists is a good way. There is no need to think much about endless tasks. Just finish them one by one.