1 . Fill in each blank with a proper word given in the box. Each word can be used only once. Note that there is one word that you do not need.

A. predictions       B. tricky       C. determine       D. consumed       E. significant F. sampled       G. address       H. concentrations       I. comparison       J. conventional       K. index

Using dragonflies as contamination(污染) detectors

Mercury(汞)pollution from power plants and mining operations can end up in our air and water.

But it’s     1     to predict just how much of that environmental mercury will make its way into our food—and our bodies.

“We were working on developing a bioindicator, a biosentinel, that could inform us of the levels of mercury contamination across the US.”

Ecologist Collin Eagles-Smith of the United States Geological Survey and his colleagues came up with a practical way to     2     the scope of mercury contamination in an ecosystem by measuring mercury levels in a single species. Their bioindicator: juvenile dragonflies, or larvae(幼虫). Dragonfly larvae stay underwater, don’t move much, are easy to collect and live long enough to accumulate     3     amounts of mercury.

“If you have enough locations     4     with dragonflies, you can develop an index of the relative amount of mercury in the biological community. ”

The team measured mercury     5     in thousands of dragonfly larvae collected from waterways in 100 national parks during a 10-year period. And to amass the large sample number, they recruited volunteers through the Dragonfly Mercury Project.

The volunteers used dip nets to collect dragonfly larvae from their aquatic abodes(住所). National park staff then sent the larvae to laboratories for processing. For     6     the researchers also measured mercury concentrations(浓度)in other aquatic organisms.

“Using the relationships between dragonfly concentrations and fish concentrations, we were able to develop what we call an impairment     7     . ”

That index allowed the researchers to make health risk    8     at each sample site.

“About 12% of the locations posed what we consider to be high or severe risk of health impairments to fish, wildlife or humans if they    9     organisms from those locations. You can begin to build models that are predictive of how much mercury might be in a system and then apply that model to locations where you haven’t sampled dragonflies.”

“And that can inform future management actions to     10     the factors that are promoting the mercury production or simply inform agencies that may want to evaluate whether or not fish consumption advisories(警告)are necessary. ”

The study is in the journal of Environmental Science & Technology.

2 . Directions: Fill in each blank with a proper word chosen from the box. Each word can be used only once. Note that there is one more word than you need.

A. wraps       B. poorly       C. generating       D. incomplete       E. sufficient       F. further G. Compressing       H. heats       I. uncertainty       J. pressurize       K. drowned

Neptune Rains Diamonds, and Now We Might Finally Know How

Deep within the hearts of Neptune and Uranus, it could be raining diamonds. Now, scientists have produced new experimental evidence showing how this could be possible.

The hypothesis goes that the intense heat and pressure thousands of kilometres below the surface of these ice giants should split apart hydrocarbon compounds, with the carbon    1     into diamond and sinking even deeper towards the planetary cores.

The new experiment used the SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS)X-ray laser for the most precise measurements yet of how this “diamond rain” process should occur-and found that carbon transitions directly into crystalline diamond.

Neptune and Uranus are the most    2     understood planets in the solar system. They are extremely far—only a single space probe, Voyager 2, has even been close to them, and only for a flyby, not a dedicated long-term mission.

The atmospheres of Neptune and Uranus are primarily made up of hydrogen and helium, with a small amount of methane. Below these atmospheric layers, a superhot, superdense fluid of “icy” materials such as water, methane, and ammonia    3     the planet’s core.

And calculations and experiments dating back decades have shown that, with    4     pressure and temperature, methane can be broken down into diamonds—suggesting that diamonds can form within this hot, dense material.

A previous experiment led by physicist Dominik Kraus used X-ray diffraction to demonstrate it. Now Kraus and his team have taken their research a step    5     . “We now have a very promising new approach based on X-ray scattering,” Kraus said about their latest efforts. “Our experiments are delivering important model parameters where, before, we only had massive    6    . The more exoplanets we discover, the more relevant this will become.”

It’s challenging to replicate the interiors of giant planets here on Earth. The first step is to heat and    7     the material to replicate the conditions inside Neptune at a depth of around 10, 000 kilometers: pulses of optical laser are     8     shockwaves in the polystyrene(聚苯乙烯), which    9     the material up to around 5, 000 kelvin. It also creates intense pressure.

In the previous experiment, X-ray diffraction(衍射)was used to then probe the material. This works well for materials with crystalline structures, but less so with non-crystalline molecules, so the picture was    10     In the new experiment, the team used a different method, measuring how X-rays scattered off electrons in the polystyrene.

This allowed them not just to observe the conversion of carbon into diamond, but also what happens to the rest of the sample-it splits off into hydrogen. And there’s pretty much no leftover carbon.

3 . 请阅读下面的篇章，并根据其内容提示，从方框中所给的8个词语中选出5个，并用其正确形式填空。

chance,     come up with,     athlete,     go up,     steady,     run through,     that,     send up

The Great Wall Marathon

The Great Wall of China is one of the new wonders of the world, with breathtaking views. In 1998 Soren Rasmussen     1     the idea of organizing a Great Wall marathon. Rasmussen and two running experts chose a route along part of the Great Wall. The marathon has taken place annually in May since 1999. In the initial event, just 292 runners participated but numbers have gone up     2    —in 2015 there were 2,500 runners from over 160 countries.

The Great Wall marathon is considered to be one of the toughest in the world. The part of the route that is actually on the Great Wall includes two exhausting up-and-down sections about 8 km long with 5,146 steps. It’s such a steep climb in parts     3     it’s hard to walk up—never mind run! The weather is hot and humid, with temperatures of around 30℃, but it can be hotter. Part of the route passes through a dry river bed with huge boulders (巨石). Runners who arrive there later in the day find it challenging because the boulders have become so hot that it’s like     4     a sauna.

So who does the marathon? Surprisingly, the marathon attracts both professional     5     and people who want to run for fun or simply do something different. Some runners stop every 10-15 minutes to take photos, chat to the locals and enjoy the scenery! If the thought of doing such a marathon horrifies you, then you can do a half marathon or an 8-km fun run instead.

4 . Finish the story with the phrases in the box.

Both Jo and I            up to            in their names          as well            A couple of years            pulled out          pretty seriously            in need

    1    ago, my wife and I    2     a gift catalogue for people    3     and invited each of our kids to choose something that we could buy     4    . When we handed the list to our nine-year-old daughter, we expected her to choose a toilet or a sewing machine or something similar. But instead, she thought it through    5     and chose village development package, which was worth    6    $5,000.     7     were surprised and ashamed, as our daughter’s generosity really challenged our finances and pushed the limits of our generosity    8    .

5 . Complete the passage with the phrases below in their proper forms.

beautiful modern road             a chorus of             dusty track             straight towards a large amount of investment            with dangerous disease

China has offered     1    to many countries in its Belt and Road Initiative. In the Congo, many     2     have been transformed into     3     since then. Trains run     4     Europe from China, and to China from Europe, bringing new jobs and opportunities to both ends. Chinese healthcare workers have also been sent to provide aid to places     5    . Despite all the difficulties involved in this project, these efforts have been greeted with     6    support from the locals.

6 . Use the correct forms of the words to complete the passage about Californians’ love for sport.

golf          premier            temporary     dive             frequency            citizen

Sport is an important part of the culture in California. Because of the good climate, Californians can spend a lot of time outdoors, so many people play a sport of some kind. The larger towns and cities have many facilities for their     1    , such as football fields, swimming pools, and    2     courses. And for those who like walking, climbing, surfing, and    3    , there are the mountains and some of the world’s     4     beaches. Californians also enjoy watching sport, so lots of people go to live sporting events     5    . The excitement and party atmosphere of live sport can make people    6     forget all their problems and relax.

7 . Complete the announcements with the correct forms of the verbs in the box. Then read them aloud.

prohibit            expect            set to            make sure          fasten             make             stow        switch off

Ladies and gentlemen, welcome onboard Flight SP432 from Beijing to Hong Kong. We are currently third in line for take-off and     1    to be in the air in about ten minutes. At this time, your portable electronic devices must    2     “flight mode” or    3     until an announcement     4    upon arrival. Smoking     5     throughout the flight. Thank you for your cooperation. Enjoy your flight!

…

Ladies and gentlemen, as we start our descent, please    6     your seats and tray tables are in their full upright position. Make sure your seat belts are securely     7    and all carry-on luggage    8     underneath the seats in front of you or in the overhead bins. Thank you!

8 . Complete the passage using the correct forms of the words in the box. Do you believe Hawking’s predictions?

pros and cons             take over            on a scientific basis            have an urge to          superior conflict with          backwards

Time travel, alien invasions, and artificial intelligence have always been popular themes in science fiction. However, these were never the exclusive domains of sci-fi writers. Some scientists also    1     explore these themes    2    . Take time travel as an example. Many fascinating stories based on time travel go either    3     or forwards in time. However, the former is not really an option. World-famous scientist Stephen Hawking once explained that travelling into the past would     4    the basic rule that cause comes before effect. But it would be possible to travel into the future in a vastly     5    spaceship approaching the speed of light. In addition to the question of time travel, Hawking also expressed his opinions on alien invasions and Al development. When many scientists and scholars were still arguing about the     6    of alien existence and AI development, Hawking said he believed aliens would invade Earth, and that humans would eventually    7     by Aland robots.

9 . Read the introduction to a science fiction novel and complete the passage using the correct forms of the words in the box.

explore             translate             discover             regard             represent            set up             recruit write             get caught up             connect

Science fiction    1     by many people as a mirror through which our future can be freely imagined and    2    . The Three-Body Problem,     3    by Chinese writer Liu Cixin, is one of those astonishing predictions about the future. The work was first published in a Chinese sci-fi magazine in 2006 and printed as a three-volume book in 2008. When the first volume    4     into English by Chinese-American author Ken Liu, it attracted attention around the world, becoming the first Asian winner of the Hugo Award for Best Novel. The book    5     many themes such as space exploration, alien contact, AI, and the future of humans.

The Three-Body Problem begins with the stories of two unrelated people, Ye Wenjie and Wang Miao. Ye     6    to join a secret project in a remote area of China, which    7     to contact alien life forms. In the other story, set 20 years later, Wang Miao     8    in a popular online game called “Three Body”, in which people live on an unknown planet with three suns. But Wang discovers it is more than a game—it uncovers a great danger threatening human existence. How are these two people’s stories     9    ? And how will their behaviour change Earth’s future and the civilisations of other planets? Answers to all these questions are waiting to     10    when you go on reading.