There is an English saying：“【小题1】” Until recently, few people took the saying seriously. Now, however, doctors have begun to look into laughter and the effects it has on the human body.  【小题2】

Tests were carried out to study the effects of laughter on the body. People watched funny films while doctors checked their hearts, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise.  【小题3】  If laughter exercises the body, it must be beneficial.

Other tests have shown that laughter appears to be able to reduce the effect of pain on the body. In one experiment doctors produced pain in groups of students who listened to different radio programs. The group that tolerated(忍耐) the pain for the longest time was the group which listened to a funny program.【小题4】

【小题5】 They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

When you were at school, were you ever told to stop daydreaming and concentrate? It was easy for your mind to wander if you weren’t interested in what you were learning or if you had better things to think about. 【小题1】 But understanding how to do it, and knowing what is distracting you, can help.

Scientists have looked at what makes us delay and found a number of ways to help us stay in the zone. 【小题2】 Research by Science Focus magazine found silence is best for concentration, or a gentle background music is great! It also found turning off notifications on your phone, or switching it off altogether, removes a major distraction and helps us focus on the task at hand.

【小题3】 Psychologists and neuroscientists are increasingly interested in our ability to settle down and have looked at what we can change inside our head to make us concentrate. An article for BBC Future by Caroline Williams says that “Attention Researcher Nilli Lavie of University College London has found that making a task more visually demanding takes up more processing power and leaves the brain nothing left to process distractions.” So, keeping your mind busy might be the answer.

【小题4】 These include making a list or timetable of the tasks you have to do, finding a workspace where you’re not attracted by other things, or chewing some gum! It’s possible the movement in your mouth occupies parts of the brain that might otherwise get distracted.

But according to Science Focus magazine, distraction isn’t all bad. “If we were always so focused that we never got distracted, we’d miss potential changes, such as threats, in our environment. 【小题5】”

Having friends is obviously good for countless reasons. And showing the world that you have lots of friends, for example on social media, seems like a winning strategy. If that is the truth, your goal is to expand your social network. Once people see how popular you are, they'll want to join that popular circle, perhaps in the hope that some of your popularity will rub off on them.

Nevertheless, can a person even have too many friends at the same time? It’s always been a misconception that if you have more friends, people will be more likely to want to be friends you.

In fact, a new study published in the Journal of Personality and Social Psychology shows that having too many friends may work against you. In a series of experiments. the authors prove that people usually prefer to befriend those who have fewer friends than they do, rather than those with more friends. The authors call this phenomenon the “friend-number paradox(悖论)”, which is also the title of their new paper.

Social ties are obviously important. Having more of these connections suggests greater social value, and more potential possibilities. So it seems reasonable to assume that people will focus their social energies on befriending people who have lots of friends already.

But the problem is that these social ties are only valuable if there’s reciprocity(互惠) involved. Friendship goes hand in hand with certain responsibilities and expectations. And people with lots of friends may not be able to fulfill those responsibilities—especially those with too many friends.   

In other words, “friendship quality” matters as much, if not more, than only the number of friends you have. Having lots of friends means your precious social resources become dilute (稀释了的), making you less able to be a good friend. And other people take that into account consciously(有意识地)or unconsciously when deciding whether to befriend you. They don’t want to spend their valuable social resources on someone who is unlikely to pay it back.