Scientists from the University of East Anglia have identified four new man-made gases that are contributing to the damage to the ozone(臭氧) layer. Two of the gases are accumulating at a rate that is causing concern among researchers.

    Worries over the growing ozone hole have seen the production of chlorofluorocarbon (CFC) gases restricted since the mid 1980s. But the precise origin of these new, similar substances remains a mystery.

    Lying in the atmosphere, the ozone layer plays a critical role in blocking harmful UV rays, which cause cancers in humans and reproductive problems in animals.

    Scientists from the British Antarctic Survey were the first to discover a huge “hole” in the ozone over Antarctica in 1985. The evidence quickly pointed to CFC gases, which were invented in the 1920s, and were widely used in refrigeration. Extraordinarily, global action was rapidly agreed to deal with CFCs and the Montreal Protocol to limit these substances came into being in 1987. A total global ban on production came into force in 2010.

    Now, the newly discovered four new gases can destroy ozone and are getting into the atmosphere from as yet unidentified sources. Three of the gases are CFCs and one is a hydrochlorofluorocarbon (HCFC), which can also damage ozone.

    The research has shown that four gases were not around in the atmosphere at all until the 1960s, which suggests they are man-made. The scientists discovered the gases by analyzing polar snow pack. Air from this snow is a natural archive of what was in the atmosphere up to 100 years ago. There searchers also looked at modern air samples, collected at remote Cape Grim in Tasmania.

    They estimate that about 74,000 tonnes of these gases have been released into the atmosphere. Two of the gases are accumulating at significant rates. However, they don't know where the new gases are being released from and this should be investigated. Possible sources include chemicals for insecticide (杀虫剂)production and solvents (溶液) for cleaning electronic components. The three CFCs are being destroyed very slowly in :the atmosphere—so even if emissions (散发)were to stop immediately, they will still be around for many decades to come.

    Of the four species identified, CFC-113a seems the most worrying as there is a very small but growing emission source somewhere, maybe from agricultural insecticides. We should find it and take it out of production.

    Confidence is a skill that many folks want to master, but have a hard time acquiring. Have you ever wondered why? Possibly you were born confident. You were talked to negatively as a child or maybe you were rejected many times. Whatever the case is{#blank#}1{#/blank#} But how to boost your confidence?

    Begin to act as if you are confident. Act as the person you would want to be like{#blank#}2{#/blank#} Surround yourself with people who you think are confident and have high value. You will learn so much from observing other confident folks.

    {#blank#}3{#/blank#}One of the most areas that you need to pay attention to is your self-talk. Your thoughts about your capabilities and self-worth need to be positive and encouraging. Whenever you notice you think negatively, pause and take a moment, and shift your focus to something that can help you feel better about yourself.

    Go after your goals. If you are really serious about building self-confidence, you need to identify your goals and go after them. The more you add to your accomplishments, the more confident you will feel about your abilities and skills{#blank#}4{#/blank#}

    By using these steps to boost your confidence{#blank#}5{#/blank#}

A. Always stay positive.

B. Improve your self-talk.

C. Begin to think and behave like them.

D. This requires you to know what a confident person looks like.

E. you will be on the path to improving your self-esteem (自尊) and self-worth.

F. You'll begin to trust your inner self more and appreciate yourself more.

G. you should know you can improve your self-esteem and build confidence.

Wilderness

    "In wilderness(荒野) is the preservation of the world." This is a famous saying from a writer regarded as one of the fathers of environmentalism. The frequency with which it is borrowed mirrors a heated debate on environmental protection: whether to place wilderness at the heart of what is to be preserved. 

    As John Sauven of Greenpeace UK points out, there is a strong appeal in images of the wild, the untouched; more than anything else, they speak of the nature that many people value most dearly. The urge to leave the subject of such images untouched is strong, and the danger exploitation(开发) brings to such landscapes(景观) is real. Some of these wildernesses also perform functions that humans need—the rainforests, for example, store carbon in vast quantities. To Mr.Sauven, these "ecosystem services" far outweigh the gains from exploitation.

    Lee Lane, a visiting fellow at the Hudson Institute, takes the opposing view. He acknowledges that wildernesses do provide useful services, such as water conservation. But that is not, he argues, a reason to avoid all human presence, or indeed commercial and industrial exploitation. There are ever more people on the Earth, and they reasonably and rightfully want to have better lives, rather than merely struggle for survival. While the ways of using resources have improved, there is still a growing need for raw materials, and some wildernesses contain them in abundance. If they can be tapped without reducing the services those wildernesses provide, the argument goes, there is no further reason not to do so. Being untouched is not, in itself, a characteristic worth valuing above all others.

    I look forwards to seeing these views taken further, and to their being challenged by the other participants. One challenge that suggests itself to me is that both cases need to take on the question of spiritual value a little more directly. And there is a practical question as to whether wildernesses can be exploited without harm.

    This is a topic that calls for not only free expression of feelings, but also the guidance of reason. What position wilderness should enjoy in the preservation of the world obviously deserves much more serious thinking.

    A new discovery may change how scientists think about prehistoric humans. Human history is more of a war movie than a romantic comedy, at least as far as other animals are concerned; we may be causing one of the planet's great extinction events at the moment. But a recent discovery means humans might not be as destructive as we thought.

    Large animals have a history of disappearing when humans move to their areas. Scientists have long believed that humans simply hunted big animals because people are really good at hunting. For example, scientists thought humans arrived in Madagascar around 4,000 years ago, but only two thousand years later, giant lemurs, giant tortoises and elephant birds disappeared from the island. Many scientists thought humans had something to do with that rapid drop in biodiversity(生物多样性).

    At least, that's what scientists thought until a group of researchers dug up a lot of bones in Madagascar recently. These bones belonged to the elephant bird, a kind of extinct bird that weighed up to 1,000 pounds. The huge bones were covered in cuts that clearly came from a human hunter. The researchers found that the humans had killed the birds 10,000 years ago...Thousands of years before scientists believed humans had come to the island.

    "Our research provides evidence of human activity in Madagascar more than 6,000 years earlier than suspected, which shows that a different extinction theory is required to understand the huge biodiversity loss that has happened on the island." explained James Hansford, one of the researchers. "Humans seem to have coexisted with elephant birds and other now-extinct species for over 8,000 years, clearly with limited negative influence on biodiversity for most of this period."

    If humans lived among large animals for thousands of years without wiping them out, then maybe our species can't wipe other species out. Rather, extinction is more of a habit we've learned. Perhaps we can unlearn it too.

    A first-year undergraduate student in Chengdu, recently complained online that her mother refused to raise her monthly allowance to 4,500 yuan ( $ 633) even when she said her current allowance 2, 000 yuan was not enough to cover her expenses, sparking a debate on how much money a college student needs per month. One expert shares his views on the issue with China Daily: Students should pursue education, not comfort.

    Even for a college student studying in a first-tier city in China, 2,000 yuan is enough to cover all his or her monthly expenses. In fact, for a college student in Chengdu a monthly allowance of 2,000 yuan is more than enough. According to a survey conducted by a bookkeeping platform, the average monthly expense for an undergraduate in cities other than Beijing, Shanghai and Hangzhou was less than 2,000 yuan in 2019； for Chengdu, it was 1,900 yuan.

    Claiming that she can hardly afford new clothing and cosmetics with her 2,000 yuan monthly allowance, the undergraduate student in Chengdu criticized her mother for refusing to raise her pocket money. Her "meager" allowance, she said, prevented her from buying branded goods that her hostel-mates enjoyed.

    By the time a person enters a college, she or he should have developed a healthy consumption habit. And a youth should adjust her or his consumption according to her or his family income. On a deeper level, the money they spend in college should depend on how much they value their parents' hard work. Besides, some college students could take UP part-time jobs to meet their monetary needs if they feel their parents don't or can't send them enough money. In this way they can also learn to meet the requirements of life in the future and develop healthy consumption habits. More importantly, they should always bear in mind that education is their top priority in college

While they are at home alone, many people imagine {#blank#}1{#/blank#} (have) the opportunity {#blank#}2{#/blank#} （sing) together, which {#blank#}3{#/blank#} (realize) by a virtual choir. Anyone can take part in {#blank#}4{#/blank#} from anywhere and does not need a studio. It {#blank#}5{#/blank#} (prove) to be a positive influence on the lives of many people. Award-winning composer and conductor Eric Whitacre came up {#blank#}6{#/blank#} the idea of the virtual choir, {#blank#}7{#/blank#} began studying music in 1988. {#blank#}8{#/blank#} (finish) university in 1995, he received a master's degree in {#blank#}9{#/blank#} (music)composition in 1997. In 2009, his first virtual choir received, {#blank#}10{#/blank#} (million) of views on the Internet. The virtual choir has become a worldwide phenomenon since then. In 2014, he formed the Virtual Youth Choir for UNICEF, and 2, 292 young people from 80 countries sang his song"What If".