How do you greet your friends? 【小题1】 —shaking hands, nodding, kissing... But have you ever wondered how animals “say hello” to others?

We know how similar chimpanzees (黑猩猩) are to humans. 【小题2】 Chimpanzees usually greet each other with a hand touch, a hug or sometimes a kiss. Some of them can also communicate through simple sign language.

Giraffes seldom make loud sounds. Male giraffes often use their necks to greet each other. 【小题3】 When two giraffes meet, they may “shake” their necks and rub them against each other. 【小题4】

Dolphins greet one another with whistles (哨声). They can hear other dolphins from many kilometers away. Every dolphin has a different whistle. 【小题5】 When two groups of dolphins meet, they each choose a member to “talk” to the other group. The two groups can then join up and travel together.

Have you ever watched a film with your friends and thought, “How wonderful!” or had a meal with your family and said, “That’s was the best!”?

Well, there may be a small secret(秘密)about why you enjoyed it so much. Our experiences are stronger if we share them with someone. That means good experiences become better, and bad ones become worse. That’s according to a new study by Yale University.

Scientists did a small study on female(女性)college students. In the test they share chocolate with someone they thought was another participant(参与者). But in fact, it was a scientist. In each test, they got two pieces of chocolate. They ate one piece at the same time with the “participant” and the other piece alone. The participants thought the chocolate was tastier and more enjoyable when they shared it with someone. Even though both pieces of chocolate were from the same box.

Scientists then did another experiment, this time with bitter, unpleasant chocolate. Again, the participants thought the chocolate was bitterer than the piece they ate alone.

“When people think of shared experience, what usually comes to mind is being with friends or Family.” said scientist Erica Boothby. “We often don’t know how much people around us influence (影响)our decisions.” according to Erica.

However, it does show that sharing things with a friend may just make your good way a little brighter. Because the study only looked at female college students, it doesn’t mean the whole   (全 部的)picture.

What did people do to communicate in ancient times? Here are some very interesting answers to this question.

Alphorns (阿尔卑斯长号角) were once used to communicate in the mountains in Switzerland. They are very long and they are very heavy, too. So, alphorns are hard work to blow. Then why use them? Well, they make a loud sound which travels much further than the human voice. Herdsmen (牧民) used them to call cows in the distance (在远处) for milking. At sunset, alphorns were also used to send a message down to villagers that all was well. These days, they’re mostly used as musical instruments.

The people of La Gomera, an island in Europe, have their own special way of sending messages from mountain to mountain. They use a whistled (口哨的) language called el silbo. El silbo comes from their language Spanish. Whistling can be heard within five kilometers, so it can be used across much greater distances than shouting. El silbo can be used for all kinds of messages, including greetings and announcements. El silbo is used a lot less than it used to be, but primary school students in La Gomera have to learn it.

Did you know it’s also possible to send messages without making a noise? This is called visual (视觉的) communication, and it includes the use of flags and even smoke. Long ago, soldiers along the Great Wall of China used smoke as a warning. If they noticed the enemy from their signal (信号) tower, they lit a smoky fire. When soldiers in other towers saw the smoke signal, they lit fires, too. In this way, messages about the enemy’s arrival could travel as far as 800 kilometers in just a few hours.

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