What is an insect? Insects of all kinds have existed on earth for millions of years. Sometimes we think of all insects as pests. Human life, however, would have a difficult time continuing without insects,
One very interesting and useful social insect is the honey bee. Bees
Another fascinating social insect is
There are also many other kinds of social insects.
2 . The beauty, majesty, and timelessness of a primary rainforest are indescribable. It is impossible to
Rainforests have
The scale of human
In 1950, about 15 percent of the Earth's land surface was covered by rainforest. Today, more than half has already gone up in
Massive
| A．present | B．capture | C．claim | D．prove |
| A．changed | B．evolved | C．expanded | D．existed |
| A．energizing | B．healing | C．isolating | D．breathing |
| A．contributed | B．stored | C．reduced | D．affected |
| A．However | B．Furthermore | C．Therefore | D．Otherwise |
| A．active | B．sensitive | C．interdependent | D．delicate |
| A．restore | B．support | C．revive | D．last |
| A．pressure | B．power | C．concern | D．strength |
| A．existence | B．ecosystem | C．planet | D．survival |
| A．unfortunately | B．consequently | C．naturally | D．similarly |
| A．store | B．food | C．smoke | D．wealth |
| A．subject | B．down | C．apart | D．victim |
| A．trend | B．practice | C．decrease | D．attitude |
| A．destruction | B．industrialization | C．modernization | D．deforestation |
| A．appearance | B．explosion | C．loss | D．increase |
阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。
A
After my husband died suddenly from a heart attack, my world crashed around me. My six children were all under 10, and I was burdened with the responsibilities of earning a living, and caring for the children. I was fortunate to find a wonderful housekeeper to care for the children during the week, but from Friday nights to Monday mornings, the children and I were alone.
One Friday evening I came home from work to find a big pretty German Shepherd（牧羊犬）on our doorstep. This dog seemed to intend to enter the house. The children liked“German”immediately and begged me to let him in. I agreed to let him sleep in the basement. That night I slept peacefully for the first time in many weeks.
The following morning we made phone calls and checked lost-and-found ads for German’s owner, but with no results.
On Sunday I had planned to take the children on a picnic. Since I thought it best to leave German behind in case his owner came by, we drove off without him. When we stopped to get gas, we were amazed to see German racing to the gas station after us. No way was he going to be left behind.
Monday morning I let him out for a run. He didn’t come back and we were all disappointed. We were convinced that we would never see him again. We were wrong. The next Friday evening, German was back on our doorstep. Again he stayed until Monday morning, when our housekeeper arrived.
This pattern repeated itself every weekend for almost 10 months. We grew more and more fond of German. We took comfort in his strong, warm presence, and we felt safe with him near us. As German became part of the family, he considered it his duty to check every bedroom to be sure each child was cozy in bed.
Each week, between German’s visits, I grew a little stronger, a little braver and more able to handle; every weekend we were no longer alone and enjoyed his company. Then one Monday morning we patted him on the head and let him out for what turned out to be the last time. We never saw German again.
1. The dog first came to the family when _______________.
| A．it was needed most |
| B．the writer became strong enough |
| C．the writer was away on a business trip |
| D．the writer was busy on the weekday |
| A．it was too wild to control |
| B．it was too young to walk so far |
| C．the owner might come by to pick it up |
| D．it might spoil the trip |
| A．afraid of | B．grateful to |
| C．cruel to | D．annoyed with |
| A．Loyal | B．Beautiful |
| C．Lovely | D．Wild |
| A. processing B. matters C. equivalent D. packaging E. essential F. producing G. changes H. supporting I. reward J. average K. special |
Eat Green: Our Everyday Food Choices Affect Global Warming and the Environment
What we eat
1. Choose Climate-Friendly Food
Food that comes from high on the food chain or arrives to your plate after extensive
2. Buy Organic and Other Sustainable Certifications
Eco—labels like USDA Organic and others give us a way to
3. Watch Your Waste
The USDA estimates that an astonishing 27 percent of all food produced for people in the United States is either thrown away or is used for a lower—value purpose, like animal food. A recent study estimated that the average household wastes 14 percent of its food purchases—a loss of significant value for most families. In addition to the water, energy, pesticides, and global warming pollution that went into producing.
4. Eat Locally
A typical American meal contains ingredients from five foreign countries, and even domestically grown produce travels a(n)
5 . The largest genetic study of mosquitoes has found their ability to resist insecticides(杀虫剂) is evolving rapidly and spreading across Africa, putting millions of people at higher risk of contracting malaria（疟疾）.
British scientists who led the work said mosquitoes’ growing resistance to control tools such as insecticide-treated bed nets and insecticide spraying, which have helped cut malaria cases since 2000, now threatens “to disturb malaria control” in Africa.
“Our study highlights the severe challenges facing public efforts to control mosquitoes and tomanage and limit insecticide resistance,” said Martin Donnelly of the Liverpool School of Tropical Medicine, who worked on the study with a team from Britain’s Wellcome Trust Sanger Institute.
Latest World Health Organization (WHO) data show that 216 million people were infected last year with the malaria parasite（寄生虫）, which is transmitted by blood-sucking Anopheles mosquitoes. The disease killed 445,000 people in 2016, and the majority of them were children in sub-Saharan Africa.
To understand how mosquitoes are evolving, the researchers sequenced the DNA of 765 wild Anopheles mosquitoes taken from 15 locations across eight African countries. Their work, published in the journal Nature on Wednesday, created the largest data resource on natural genetic variation for any species of insect.
Analyzing the data, the scientists found that the Anopheles gamblae mosquitoes（冈比亚疟蚊）were extremely genetically diverse compared with most other animal species. This high genetic diversity enables rapid evolution, they said, and helps to explain how mosquitoes develop insecticide resistance so quickly.
The data also showed the rapid evolution of insecticide resistance appeared to be due to many previously unknown genetic variants（变体）within certain genes. The scientists said these genetic variants for insecticide resistance were not only emerging independently in different parts of Africa, but were also being spread across the continent by mosquito migration.
Michael Chew, an expert at Britain’s Wellcome Trust global health charity which helped fund the research, said the finds underlined the importance of pushing scientific research ahead to control malaria.
Global efforts to control malaria through effective vaccine, insecticides and the best drug combinations require urgent, united action by scientists, drug companies, governments and the WHO.
1. Which of the following is scientists’ headache?| A．The number of mosquitoes in Africa is growing rapidly. |
| B．Some genetic variants of mosquitoes are still unknown. |
| C．The existing insecticides aren’t as effective as they used to be. |
| D．Millions of African people have resistance to medicines for malaria. |
| A．threatening drug companies | B．spraying insecticides |
| C．limiting blood donation | D．transmitting data |
| A．Children are more likely to be bit by mosquitoes. |
| B．Many previously unknown variants are found in the study. |
| C．The mosquito migration contributes to the spread of variants. |
| D．Anopheles mosquitoes have great genetic diversity. |
| A．It created the largest data on natural genetic variation for any insect species. |
| B．It found the possible causes for the rapid evolution of insecticide resistance. |
| C．It discovered where the genetic variants emerged and how they were spread. |
| D．It highlighted the public efforts and appealed to limit the use of insecticides. |
Does City Living Hurt Mental Health?
People often move to cities
Experts at the American Psychiatry Association say that “natural environments or green spaces” do much for good our mental health and
On the other hand,
Andrea Mechelli is a doctor with the Institute of Psychiatry at Kings College, London. “There have been studies
Kings College researchers, along with city planners and land and building designers hoped
The Urban Mind app
The researchers found that being outdoors, seeing trees, hearing birdsong, seeing the sky, and feeling in contact with nature
The Urban Mind Project team says it hopes “the results will inform future urban planning and social policy
Surviving in the Wilderness
Many people enjoy travelling through wild and deserted landscapes, but few expect to end up in a genuine survival situation. The unexpected occasionally
Priority 1 Shelter
Do not put off
Priority 2 Water
If you fail to find water, you will only survive for about three days (whereas you can survive for weeks without food). If there is no rain, try walking through vegetation early in the morning to collect moisture in clothing. Avoid drinking water
Priority 3 Fire
Fire has many uses. It makes food more appetizing. If you can’t face eating raw worms, boil them in water to make a nourishing soup! Fire protects
Priority 4 Food
It is quite easy to get food in the wild, if you know where to look. Many survival books suggest eating a small amount of unknown plants to test
8 . Throwing handfuls of bread to birds has long been seen as harmless enough. But in recent years, some scientists have suggested that bread might not do birds’ digestive systems any good, saying that as uneaten food rots down, the water quality worsens and algal blooms can occur. Plus, by encouraging birds to gather in one place, the build-up of droppings may result in outbreaks of disease too. Meanwhile, many cities have signs telling us not to feed pigeons and gulls, which are considered an “annoyance” due to the mess they make, and scattering bread inevitably attracts rats and mice.
It seems that the public has accepted these warnings, and that fewer of us now feed birds this way. In October, a sign went up in a Derbyshire park claiming that the local birds were dying of starvation, and urging visitors to feed them as before. When online posts about the notice went viral, feathers flew as people debated the benefits of handing out bread to birds.
Paul Stancliffe of the British Trust for Ornithology(BTO) points out that there’s insufficient scientific evidence for bread harming birds, adding that, as little research has been done, it could even turn out to be beneficial. ① “We just don’t know,” he says. Although bread is a heavily processed “unnatural” food intended for humans, that alone may be insufficient grounds for not feeding it to birds.
In the 1980s, the Wildfowl & Wetland Trust (WWT) carried out a comparative study of different flocks of mute swans, and the birds that consumed the most bread had weaker muscles, implying that a bread-heavy diet might be the cause. “Our official line is that bread is okay for ducks, geese and swans, but only in moderation,” says WWT’s Peter Morris. “However, this advice comes with several other warnings.” ② The first is that it’s best offered in winter, when there is less plant and insect food around. In spring and summer, too much artificial food may not be a good idea, since young birds have to learn how to look after themselves and natural food will contain a wider range of nutrients to help them grow.
“Just like us, birds need a varied diet to stay healthy,” says a spokesperson for the Royal Society for the Protection of Birds(RSPB). “Although ducks, geese and swans can digest all types of bread, too much can leave them feeling full without giving them all of the important vitamins, minerals and nutrients they need.” ③
When bird feeding first became popular in the UK in the 19th century, some Victorians encouraged tough love, arguing that such handouts would only make our feathered friends lazy and dependent on welfare. ④ Morris says that there is a theory that wild birds can get “hooked” on easy meals, losing interest in other types of food. Another danger, he says, is that birds fed regularly end up accustomed to humans, placing themselves at greater risk of predation(捕食).
1. How can feeding birds with bread affect our urban life?| A．Birds’ mess can attract many rats and mice. |
| B．Birds’ gathering in one place disturbs our peace. |
| C．Bread goes bad and the water quality will suffer. |
| D．Human beings are likely to be infected with bird flu. |
| A．they will become bigger in size with stronger muscles |
| B．lack of certain nutrients negatively influences their health |
| C．their digestive system will be damaged by artificial food |
| D．they would soon choose bread rather than natural food |
| A．① | B．② | C．③ | D．④ |
| A．Is feeding birds a wise choice? | B．Why not feed our bird neighbours? |
| C．Can we treat birds as friends? | D．When do birds need our food aid? |
| A．The impact of animal studies. |
| B．The growing population. |
| C．The loss of natural habitats. |
| D．The birds’ changing behaviour. |
| A．It can contribute to the better conservation of birds. |
| B．It is aimed at solving mysteries about nature. |
| C．It is funded jointly by four nature organizations. |
| D．It has spotted at least 10 birds not seen for a long time. |
| A．The benefits of bird conservation. |
| B．The search for lost birds. |
| C．The reasons for bird extinction. |
| D．The organizations of bird protection. |
The Decline of Biodiversity
Biodiversity is the range of living things in an area. During the last 100 years, scientists have seen a great decline in biodiversity. Some studies show that one in eight plant species is threatened with extinction. It is estimated that 140,000 species of plants are lost each year.
Most of the extinctions in the last thousand years are due to humans. The main cause is the chopping down of tropical rain forests. Most of this destruction is done to create pasture (牧场) for beef cattle. Many rainforests in Central and South America have been burnt down to make way for cattle farming, which supplies beef to the rest of the world. It is estimated that for each pound of beef produced, 200 square feet of rainforest are destroyed. The forests are also cut down to make wheat for bread as well as fruit for human consumption.
The introduction of exotic (外来的) species is another threat. The latest research from the University of Southampton has revealed the impact of exotic species upon native wildlife, which could potentially lead to the extinctions of local species. When exotic species are introduced to a place, they try to establish a self-sustaining population. While the local species, which haven’t had a chance to evolve, often lack defenses and thus cannot compete against the exotic species.
The disappearance of certain food animals can be disastrous not only to larger animals but also to the entire ecosystem. It is these small creatures which convert much of the energy in an ecosystem from unusable (i.e. microscopic plants, decaying matter, etc.) into usable forms, namely their bodies. Their absence makes most energy and nutrients trapped in forms unusable to other species. This makes the environment less suitable for healthy living, and less capable of producing resources that humans need.
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