1 . African grey parrots help their peers complete tasks despite no immediate benefit to themselves, researchers have found in the first study to show that birds display such apparently “selfless” behaviour.

Writing in the journal Current Biology, Brucks and colleagues report how they tested African grey parrots in a task that involved the birds passing a token, in the form of a metal ring, through a hole in their section to a neighbouring bird of the same species. This token could then be passed by the second bird to a human, via another hole, who would exchange it for a piece of nut.

The team found African grey parrots helped their neighbours by passing tokens to their neighbour when a human held out their hand, allowing the second bird to drop it through-the hole and receive a tasty treat.

The same behaviour was seen when the roles of the birds were reversed (颠倒). The more tokens a bird had previously given, the more they received in return.

However, the team stress previously the birds did not know that their favour would be rewarded, suggesting it is something of a “selfless” act.

The team say it may be due to African grey parrots gathering in huge flocks at night but splitting into smaller groups during the day to forage (觅食). Brucks said such behaviour is thought to require strong social cognitive abilities, adding that being helpful might help the birds gain a good reputation with their peers, making it more likely that they would team up for foraging and other tasks.

Dr Manon Schweinfurth, an expert in animal behaviour, said evidence of reciprocal (互惠的) behaviour in African grey parrots is quite interesting. “It has been thought that it is so cognitively demanding that only humans can show it. But we now get more and more evidence from other animals that they are able to show reciprocity,” she said.

2 . What are the speakers talking about?

7 . Self-confidence is about trusting your judgement and your ability to do something well. It is also about being willing to consider the possibility that you are wrong and change your mind. It is a combination of courage and humility, which leads to open-minded thinking.       1    . It often prevents you from doing your best and perhaps from even trying. When you do try, your lack of trust in yourself may ultimately lead you to fail.

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·One of the reasons is the home environment where children grow and develop. They may find it difficult to develop self-confidence if their parents are critical or overprotective. Once they fail to fulfill expectations, they may feel bad about themselves and get trapped in the cage of self-doubt.

·    3    . If a child gets discouraged at school or in the neighbourhood, he or she may be afraid of speaking in public, even when he or she grows up to be an adult.

·Work on positive thinking. A positive attitude will lead to positive results. Go for it and don’t worry about letting others down.     4    . Turn your negative thoughts into positive ones. You can always talk to yourself in a positive way, such as “I can do it!” or “I’ll give it another try!”.

·Set realistic goals for yourself and visualize yourself achieving these goals.     5    . It is important to break down the overall goal into smaller and more measurable tasks. For those tasks you are not so sure about, ask your friends or family for advice. Also understand that it is perfectly normal if you do not succeed in completing a task.

It has proved by scientists using hidden cameras that when only one or two people ride in a lift, they usually lean against on the walls. If four people are aboard, they usually moved towards the four corners. So, when the population reaches five and six people, everyone begins to obey more formal rules of lift etiquette. They all turn to face the door. “They get taller and thin,” as a professor describes it. “Hand and purses hang down in front of their bodies. They mustn’t touch each other in any way if the lift is crowded and then only lightly at the shoulder or the upper arm. Also there are a behavior to look upward at the floor indicator. If they speak, it is definitely in the low voice.”

May 21st this year marks the first International Tea Day, which was named officially     1     the United Nations on November 27th, 2019. To celebrate     2     festival, a number of events took place at the Chinese Businessman Museum in Beijing on Thursday.

The chairman of the China Culture Promotion Society     3     (address) the opening ceremony. “As a main promoter of the International Tea Day, the birthplace of tea and the     4     (large) tea­producing country, China has a     5     (responsible) to work with other countries to promote the healthy development of the tea industry. It can help to build a community with a     6     (share) future for mankind,” he said.

The “First International Tea Day Tea Road Cooperative Initiative” issued (发布) at the ceremony calls for people working in the tea industry to come together to promote international cooperation     7     cultural exchanges. A four­year tea promotion — Tea Road Cooperative Plan — was also issued in accordance with the initiative.

    8     (strengthen) the connection with young people, the event included a number of public promotional activities on social media,    9    (invite) twenty­nine tea professionals from around the world to have thirty­six hours of uninterrupted live broadcasts.

The Chinese Ancient Tea Museum was officially unveiled (揭幕) at the ceremony, opening     10     (it) first exhibition: The Avenue of Truth—A Special Exhibition of Pu’er Tea.

Best wishes.