【推荐2】Covid-19 is not the only catastrophe that 2020 has brought. In parts of Asia and east Africa, swarms（成群）of locusts（蝗虫）have destroyed fields. Locusts are usually inoffensive, spread-out creatures that do not stay far from the place where they were born. But under the right circumstances, that is, a heavy rain and a following boom in plant growth, they can be gregarious. Millions of the insects gather in swarms which can fly more than 100km in a day.

In a paper published in Nature, Xiaojiao Gou and a group of other researchers clarify part of the biochemical system that drives that transformation. Dr Gou and her colleagues collected 35 chemicals acquired from the bodies and wastes of locusts. When tested, locusts were strongly attracted to just a chemical, one called 4-vinylanisole （4VA）. Scientists already know that swarming is a response to overcrowding, and Dr Gou and her colleagues found that 4VA production rose with population enlargement. Further investigation confirmed the odour receptor （气味受体）on the insects' antennae（触角）is sensitive to the chemical.

Humans have tried everything they can to deal with locust swarms, with mixed results. Man-made version of 4VA might be used to bait（诱捕）traps. If 4VA turns out to be a language that all locusts understand, then it may help humans persuade them to abandon their gregarious ways, and return to a peaceable life of being alone.

1. What does the underlined word in Paragraph 1 mean?

A．Flexible.	B．Starved.
C．Aggressive.	D．Gathering.

2. What did Dr Gou's group find?

A．Locusts can release 35 chemicals from their bodies.

B．4VA is one of the chemicals strongly attracting locusts.

C．4VA will be produced more when locusts' number increases.

D．The transformation of locusts affects the biochemical system.

3. What can we infer from the last paragraph?

A．Humans have got the methods of killing locusts.

B．Man-made version of 4VA will be introduced to market.

C．Scientists have had a new breakthrough to transform locusts' habitats.

D．It remains to be proved whether 4VA is a language that locusts understand.

4. What does the passage mainly talk about?

A．The harm caused by locust swarms.

B．The ways to prevent locust swarms.

C．The process of locusts' transformation.

D．The finding of 4VA attracting locust swarms.

【推荐1】Everybody loves a fat pay rise. Yet pleasure at your own can vanish if you learn that a colleague has been given a bigger one. Indeed, if he has a reputation for slacking(懈怠的), you might even be outraged. Such behaviour is regarded as “all too human,” with the underlying assumption that other animals would not be capable of this finely developed sense of grievance(不满). But a study by Sarah Brosnan and Frans de Waal of Emory University in Atlanta, Georgia, which has just been published in Nature, suggests that it is all too monkey, as well.

The researchers studied the behaviour of female brown capuchin monkeys. They look cute. They are good-natured, co-operative creatures, and they share their food readily. Above all, like their female human counterparts, they tend to pay much closer attention to the value of “goods and services” than males.

Such characteristics make them perfect candidates for Dr. Brosnan’s and Dr. de Waal’s study. The researchers spent two years teaching their monkeys to exchange tokens for food. Normally, the monkeys were happy enough to exchange pieces of rock for slices of cucumber. However, when two monkeys were placed in separate but adjoining chambers, so that each could observe what the other was getting in return for its rock, their behaviour became markedly different.

In the world of capuchins, grapes are luxury goods (and much preferable to cucumbers). So when one monkey was handed a grape in exchange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without having to provide her token in exchange at all, the other either tossed her own token at the researcher or out of the chamber, or refused to accept the slice of cucumber. Indeed, the mere presence of a grape in the other chamber (without an actual monkey to eat it) was enough to induce resentment in a female capuchin.

The researchers suggest that capuchin monkeys, like humans, are guided by social emotions. In the wild, they are a co-operative, group-living species. Such co-operation is likely to be stable only when each animal feels it is not being cheated. Feelings of righteous indignation(愤慨), it seems, are not the preserve of people alone. Refusing a lesser reward completely makes these feelings abundantly clear to other members of the group. However, whether such a sense of fairness evolved independently in capuchins and humans, or whether it stems from the common ancestor that the species had 35 million years ago, is, as yet, an unanswered question.

1. In the opening paragraph, the author introduces his topic by ___________.

A．making a conclusion	B．justifying an assumption
C．explaining a phenomenon	D．making a comparison

2. The statement “it is all too monkey” (Last line, Paragraph 1) implies that __________.

A．monkeys are also outraged by slack rivals

B．feeling angry about unfairness is also monkeys’ nature

C．monkeys, like humans, tend to be jealous of each other

D．no animals other than monkeys can develop such emotions

3. Dr. Brosnan and Dr. De Waal have eventually found in their study that the monkeys _________.

A．prefer grapes to cucumbers

B．can be taught to exchange things

C．will not be co-operation if feeling cheated

D．are unhappy when separated from others

4. What can we infer from the last paragraph?

A．Monkeys can be trained to develop social emotions.

B．Human indignation evolved from an uncertain source.

C．Animals usually show their feelings openly as humans do.

D．Cooperation among monkeys remains stable only in the wild.

【推荐2】Sometimes we may find that every week there are a lot of new stories about how climate change is affecting the planet, or new plans to battle its effects. But the concept itself isn't new at all — in fact, scientists have been exploring questions about climate change for almost 200 years.

The idea of “greenhouse gases” goes back to 1824, when Joseph Fourier wondered what was regulating the earth’s temperature. Fourier concluded that the atmosphere must be responsible for containing the heat absorbed from the sun and described it as a box with a glass lid: As light shines through the glass, the inside gets warmer as the lid traps the heat. As Fourier's ideas spread, it came to be called “the greenhouse effect”.

Scientists continued to study the greenhouse effect. Not until a Swedish chemist named Svante Arrhenius came along, did scientists understand how global warming actually works. After years of work, Arrhenius determined that the level of carbon dioxide in the atmosphere did in fact have a direct effect on global temperatures.

Arrhenius found that CO2, and other gases trap radiation, which warms the atmosphere. Arrhenius was the first to suspect that burning coal could contribute to the greenhouse effect. But Arrhenius welcomed the warming effect on the planet. At a lecture later that year, Arrhenius noted that creatures of a warmer earth “might live under a milder sky and in less barren surroundings”.

While Arrhenius’ findings won him the 1903 Nobel Prize in chemistry, scientists kept debating whether the greenhouse effect was increasing until 1950, when researchers finally began to find strong data supporting it. By the end of the 1950s, American scientists had been sounding the alarm on the long-term consequences of climate change. Climate change research has come a long way since Fourier first described the greenhouse effect — still, maybe Arrhenius should have been more careful of what he wished for.

1. What does the underlined word “it” in Paragraph 2 refer to?

A．The climate change.	B．The greenhouse effect.
C．The atmosphere.	D．The heat from the sun.

2. What's the author's attitude towards Arrhenius’ wish?

A．Optimistic.	B．Negative.
C．Neutral.	D．Ambiguous.

3. What's the main idea of the text?

A．Causes of climate change.

B．Effects of greenhouse gases.

C．Findings about global warming.

D．Explorations on climate change.