1 . Nothing feels more like summer than a neighborhood barbecue. But the annoyance of summer gatherings remains: the buzzing(嗡嗡声) of mosquitoes around our ears.

“The buzzing in your ear is mostly just a side effect of the mosquito's wings beating,” said Michael Riehle, a professor at the University of Arizona. “The sound doesn't have a long range, so you notice it most when they are flying around your ears.”

“From a distance, mosquitoes track carbon dioxide that we give out.” Riehle told Live Science. “They fly back and forth to follow that concentration level back to the source.”

But in fact, that buzzing you hear is likely from a female mosquito. That's because male and female mosquitoes lead very different lives. The males typically hang out and feed on the sweetest part of flowers; they couldn't care less about the humans wandering about. The females, however, need to find a blood meal in order to have enough energy to produce eggs.

As she approaches, the female mosquito zeros in on body heat and the carbon dioxide to land on the victim. The female mosquito uses taste sensors on her feet to determine whether the human, or any blood-bearing animal, is adequate to tap for her next meal.

But while we feel mosquitoes buzzing around our ears, Riehle noted that most mosquitoes are not attracted to our heads. Rather, these bloodsuckers may be more likely to seek out our feet, which have bacteria that give off attractive smell to mosquitoes. However, most people probably don't notice a mosquito buzzing around their ankles, he said.

Another study found that female mosquitoes were more attracted to men who had less diverse bacteria on their skin than to men with more diverse skin bacteria; these bloodsuckers also prefer those who wear dark colors, such as black.

1. What attracts mosquitoes to our head?

A．There is most carbon dioxide.	B．The face skin is easy to stick in.
C．There exists their favorite smell.	D．They can suck most blood there.

2. What do female mosquitoes use to determine a meal?

A．Her nose.

B．Her sensors.

C．Her eyes.

D．Her ears.

3. What color might help avoid mosquitoes most according to the text?

A．Black.

B．Blue.

C．White.

D．Red.

4. What can be the best title for the passage?

A．Why do mosquitoes buzz in our ears?

B．How can we avoid the buzzing of mosquitoes?

C．How are male and female mosquitoes different?

D．What effect does the buzzing of mosquitoes have?

2 . One billion people in the world are short of water. How can this problem be solved. Some suggestions have been to desalinate ocean water or to build enormous water pipelines from areas where water is abundant. (Suggestions such as these prove extremely expensive when they are actually used.) One possibility that scientists are considering is pulling icebergs from either the North Pole or the South Pole to parts of the world with a water shortage. Although many questions must be answered before such a project could be tried, moving icebergs seems a reasonable possibility in the future.

Engineers, mathematicians, and glaciologists from a dozen countries have been considering the iceberg as a future source of water. Saudi Arabia is particularly interested in this project because it has a great water shortage. Scientists estimate that it would take 128 days to transport a large iceberg (about 1/2 square mile) to Saudi Arabia. Yet the iceberg would be completely melted by the 104th day. Therefore, insulation would be essential, but how to insulate the iceberg remains an unsolved problem.

The problems in transporting an iceberg are numerous. The first problem is choosing the iceberg to pull. The icebergs that form in the North Pole are quite difficult to handle because of their shape. Only a small portion extends above the water — most of the iceberg is below the surface, which would make it difficult to pull. South Pole icebergs, on the other hand, are flat and float like table tops. Thus they would be much easier to move.

How can a 200-million-ton iceberg be moved. No ship is strong enough to pull such enormous weight through the water. Perhaps several ships could be used. Attaching ropes to an iceberg this size is also an enormous problem. Engineers think that large nails or long metal rods could be driven into the ice. What would happen if the iceberg splits into several pieces during the pulling. Even if an iceberg with very few cracks were chosen, how could it be pulled through stormy waters. Furthermore, once the iceberg reached its destination, very few ports would be deep enough to store it.

All of these problems must be solved before icebergs can become a reasonable source of water. Yet scientists estimate that it will be possible to transport them in the near future. Each year, enough icebergs form to supply the whole world with fresh water for a full year. In addition, icebergs are free and nonpolluting. As a solution to the world’s water problems, icebergs may be a workable possibility.

1. What is a problem in transporting iceberg?

A．The size of the iceberg.

B．The colour of the iceberg.

C．The salt in the iceberg.

D．The movement of air and water.

2. What is the author’ attitude towards transporting iceberg?

A．Pessimistic.	B．Objective.
C．Optimistic.	D．Unconcerned.

3. What does the last paragraph mainly tell us?

A．It is hard to use iceberg.	B．Iceberg are a good choice.
C．There are problems with iceberg.	D．Man finds no other ways to solve water shortage.

4. What can be a suitable title for the text?

A．Shortage of water.	B．Icebergs for water.
C．Scientists and icebergs.	D．Iceberg—scientists headache.

3 . Most animals living in crowded conditions have particularly strong immune systems, so it long puzzled researchers that honeybees do not.

Part of the answer, discovered in 2015, is that queen bees vaccinate their eggs by moving parts of proteins from disease-causing pathogens to them before they are laid. These act as antigens to trigger the development of a protective immune response in the developing young. But that observation raises the question of how the queen receives her antigen supply in the first place? Dr. Harwood wondered if the nurse bees were taking in parts of pathogens and passing them to royal jelly they were producing while eating the food brought to the hive.

To test this idea, he teamed up with a group at the University of Helsinki, in Finland, led by Dr Heli Salmela. Together, they collected about 150 nurse bees and divided them among six queenless mini hives equipped with baby bees to look after. Instead of honey, they fed the nurses on sugar water, and for three of the hives they added P. larvae, a bacterium causing a hive-killing disease, to the sugar water.

In this case, to stop such an infection happening, Dr Harwood and Dr Salmela heat-treated the pathogens and so killed them in advance. They also labelled the dead bacteria with a fluorescent dye, to track them easily. And, sure enough, it was confirmed that parts of P. larvae were getting into royal jelly released by those bees which had been fed with the sugar water containing that.

All told, these findings suggest that nurse bees are indeed, through their royal jelly, passing antigens onto the queen for vaccinating her eggs. They also mean the nurses are vaccinating baby bees as well, because baby bees, too, receive royal jelly for the first few days after they come out.

1. What does the underlined word “trigger" in Paragraph 2 probably mean?

A．Cut out.

B．Set off.

C．Slow down.

D．Put off.

2. Which is the main experimental subject in Paragraph 3?

A．Queen bees.

B．Nurse bees.

C．Bee eggs.

D．Baby bees.

3. Why was P. larvae added to the sugar water?

A．To test if it would cause a hive-killing disease.

B．To check how the bacterium would affect the hive.

C．To see whether the target bees would favor the taste.

D．To confirm the bees would pass pathogens to royal jelly.

4. What is the text mainly about?

A．How bees multiply.	B．How antigens function.
C．How bees get vaccinated.	D．How immune system works.

4 . 阅读下面材料，在空白处填入1个适当的单词，或括号内单词的正确形式。

“Animals are a who, not a what,” animal advocates say. Animal rights activists, including Jane Goodall, want writers —     1     take guidance from the Associated Press Stylebook — to stop referring to an animal as “it.”

Animals are a part of some of the most important     2    （story）being told right now, but they are not always given     3     voice. We have learned much about how intelligent, social, complex and unique as individuals they are, and we know they are important. But many times, they     4    （describe）as if they are merely objects whose lives and interests don't deserve further     5    （consider）on our part.

Jane Goodall points out that when she     6    （start）her research, she was told that her findings and approaches, such as     7    （give）names to chimpanzees, were wrong. She was told that the belief that they have emotions was also     8    （correct）.

“But we know that animals feel joy, pain     9     grieve; We are not separate     10     other species,” Goodall adds. We must recognize that every individual nonhuman animal is a ‘who,' not a ‘what.'

5 . One of the greatest challenges in caring for such intelligent animals as chimpanzees (猩猩) is providing them with enriching experiences. Every day, the chimpanzees at Project Chimps receive morning and evening food-based enrichment devices, but caregivers are always looking for more ways to keep the chimps mentally engaged. With 79 chimpanzees, each with their distinctive personality, care staff often find that different chimps react differently to new enrichment.

Last year, we began inviting musicians to perform for chimps to see what they may respond. A violin performance received quite the response. Additional musicians were lined up to visit but the coronavirus has stopped the activities, which we hope to resume in the near future.

This past week, we brought an electric piano for the chimps to investigate. Some chimps, like twins Buttercup and Clarisse, were immediately interested and could not wait to tap out a few notes. Others, like Emma, were more interested in trying to take it apart.

29-year-old Precious has very little tolerance for the piano. She sat off to the side for a few minutes, but eventually she decided that was enough. She called an end to the enrichment session by throwing a handful of waste at the piano. Receiving her message loud and clear, we removed the piano.

We could never have guessed how 33-year-old Luke would react to it. As with many retired lab chimpanzees, Luke has some anxiety issues. He seems particularly distrustful of anything new, including people, food, and enrichment. But when we presented the chimps with the piano, Luke was the first to investigate. We could not believe our eyes—this usually anxious chimpanzee bravely chose to explore something new!

To us at Project Chimps, this is what it is all about: giving chimpanzees the freedom to choose. We are honored to be part of their journey.

1. Why do chimpanzees respond differently to new enrichment?

A．They are of different genders.

B．They have natural curiosities.

C．They are as intelligent as humans.

D．They have their unique characters.

2. Who showed the least interest in the piano?

A．Buttercup and Clarisse.

B．Emma.

C．Precious.

D．Luke.

3. What does the underlined word “resume” in Paragraph 2 mean?

A．Continue.

B．Suspend.

C．Monitor.

D．Regulate.

4. What is the text mainly about?

A．How caregivers care for the retired chimpanzees.

B．What care staff do to enrich chimpanzees’ daily life.

C．How chimpanzees are trained through various enrichment.

D．What Project Chimps does to observe and study wild chimps.

6 . British sculptor Jason Taylor has made it his mission to use his talent to conserve our ecosystems by creating underwater museums. Over the years, the environmentalist has put over 850 massive artworks underwater worldwide. On February 1, 2021, Taylor launched his latest work---The Underwater Museum of Cannes.

“The main goal was to bring attention to the fact that our oceans need our help,” Taylor told Dezeen. “Ocean ecologies have been destroyed by human activity in the Mediterranean over the past few decades, and it is not obvious what is taking place when observing the sea from afar.”

The Underwater Museum of Cannes contains 6 sculptures featuring local residents of various ages. They range from Maurice, an 80-year-old fisherman, to Anouk, a 9-year-old student. Towering over 6-feet-tall and weighing 10 tons, the faces are sectioned into two parts, with the outer part like a mask. The mask indicates that the world’s oceans appear powerful and unbeatable from the surface but house an ecosystem that is extremely fragile to careless human activities.

Though the waters surrounding the sculptures now appear a pristine blue, the seabed was filled with old boat engines, pipes, and other human-made trash when the project began about four years ago. Besides removing the trash, Taylor also restored the area’s seagrass. Just one square meter of the seagrass can generate up to 10 liters of oxygen daily. The seagrass also helps prevent coastal erosion and provides habitats for many ocean creatures.

“The idea of creating an underwater museum was to draw more people underwater and develop a sense of care and protection,” Taylor told Dezeen. “If we threw unwanted waste near a forest, there would be a public outcry. But this is happening every day in our surrounding waters and it largely goes unnoticed.”

1. What are the underwater museums intended to do?

A．To make huge profits.	B．To raise awareness of protecting the ocean.
C．To show Jason Taylor’s talent.	D．To draw attention to endangered sea animals.

2. Why does the outer part of the sculptures look like a mask?

A．To popularize the features of the locals.

B．To remind people to protect themselves.

C．To reflect people’s protection of the ocean.

D．To stress the sensitiveness of the ecosystem.

3. What’s Paragraph 4 mainly about?

A．How the project was started.	B．How the seagrass was restored.
C．What recovery effort the project made.	D．Why the surroundings were improved.

4. What can we infer from what Jason Taylor said in the last paragraph?

A．The situation of the ocean is easily ignored.

B．The destruction caused to the ocean is noticeable.

C．Forests play a more important role in ecosystems.

D．People have zero tolerance to damage done to nature.

7 . Shining just 12 light-years from Earth, the star Tau Ceti so resembles the sun that it has appeared in numerous science- fiction stories and was the first star astronomers ever searched for signs of intelligent life, half a century ago. In 2012 Tau Ceti grew still more interesting when astronomers reported five possible planets somewhat larger than Earth circling closer to the star than Mars orbits (围绕……运动) the sun—one of which is in the star’s habitable zone. Newly released images taken by the Herschel Space Observatory provide even more insight about Tau Ceti’s solar system: greater detail about its dust belt.

Dust arises when asteroids and comets (小行星和彗星) crash into one another, so its location reveals where these dust- creating objects—which are too small to be seen directly—orbit a star. In Tau Ceti’s case, “it’s quite a wide dust belt,” says Samantha Lawler of the University of Victoria in British Columbia. As her team reported in November, the belt’s inner edge is roughly two to three astronomical units (AUs) from the star, which is the position of our own sun’s asteroid belt. (An AU is the distance from Earth to the sun.) Tau Ceti’s dust belt extends out to 55 AU, which would be just beyond our system’s main Edgeworth-Kuiper belt, the zone of small bodies whose largest member is probably Pluto. Presumably full of asteroids and comets, Tau Ceti’s dust belt most likely lacks a planet as large as Jupiter, Lawler says. The gravity of such a massive planet would have driven away most small space rocks.

Within a year a new series of radio telescopes in Chile called ALMA should provide a sharper view of the disk, especially of its inner edge. The ALMA images will help astronomers confirm whether the star’s five proposed planets are indeed real. If the disk overlaps the planets’ hypothesized (假设的) orbits, then they probably do not exist; they would have kept away most asteroids near the star, removing the source of dust.

If those planets do exist, however, Lawler’s team suggests that Tau Ceti’s planetary system may resemble what our solar system would have looked like had the four giant planets—Jupiter, Saturn, Uranus and Neptune- never formed: small planets orbiting close to the star, and nothing but asteroids, comets and dust beyond.

1. According to astronomers, the five possible planets of Tau Ceti________.

A．resembled Earth in size

B．functioned like a solar system

C．were located in Tau Ceti’s habitable zone

D．were nearer to Tau Ceti than Mars to the sun

2. Which of the following is true of Tau Ceti’s dust belt?

A．It is narrower than the asteroid belt in our system.

B．The bodies inside it are all smaller than Jupiter.

C．The gravity of Tau Ceti makes it get denser.

D．It is over 55 astronomical units in width.

3. According to the passage, the five planets are most likely to exist if________.

A．they don’t move into the dust belt while orbiting Tau Ceti

B．they have kept away most asteroids and comets

C．they don’t crash into any asteroid or comet

D．they can be seen clearly by ALMA

4. It can be inferred from the passage that Tau Ceti’s dust belt________.

A．is useful because it stops asteroids or comets crashing into the star

B．makes Tau Ceti different from the sun because it extends farther

C．is interesting because it keeps other planets away from Tau Ceti

D．plays a role in helping decide whether the five planets are real