【推荐1】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 word more than you need.

A. qualities     B. continued     C. bodies     D. essential     E. transformations F. described     G. geological     H. shaped     I. estimated     J. cultivated     K. evolved

For the first time, scientists have mapped the whole surface of Titan, the largest moon around Saturn. The map confirms existing data showing that Titan has many Earth-like     1     that might be able to support life.

The data was collected by Cassini, a spacecraft operated by the U.S. space agency NASA. The spacecraft studied Saturn and its moons from 2004 to 2017. Astronomers used images and radar measurements from Cassini to create the     2     map of Titan.

The map shows Titan as a mixture of flat plains, hills and mountains, windblown sand areas, valleys and lakes. The mapping operation is     3     in a report published in Nature Astronomy.

Rosaly Lopes led the project. She is a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. Lopes told the publication that the many similarities between Earth and Titan make the Saturn moon a great choice for     4     exploration.

“Titan has an atmosphere like Earth's. It has wind; it has rain; it has mountains,” Lopes said.

Titan is the only planet in our solar system besides Earth to have known     5     of liquid on its surface. But Titan's seas and lakes are filled with liquid methane (甲烷) rather than water.

At cold temperatures, methane goes through similar     6     as rain does on Earth. It falls to the surface across the planet to form rivers and lakes and can then evaporate (挥发) to form clouds again.

The map found that nearly two-thirds of Titan's surface is made up of flat plains, Nature reported. About 17 percent is covered in sandy hills     7     by the wind, mostly around the equator.

Unlike Earth, Titan's sand is made up of carbon, hydrogen, nitrogen and oxygen. Around 14 percent of the surface is considered hilly or mountainous. Seas and lakes filled with liquid methane cover a(n)     8     1.5 percent of Titan. The liquid exists mainly closer to the planet's poles, while the equatorial areas remain drier.

Rosaly Lopes says organic materials --- those containing carbon --- in Titan's atmosphere are     9     for the growth of living organisms. “Organics are very important for the possibility of lifeon Titan, which many of us think likely would have     10     in the liquid water ocean under Titan's icy crust (硬的表面),”she said.

【推荐2】阅读下面小短文，根据上下文语境，选择合适的单词填入空白处，每个单词只使用一次，每个语篇有一个是多余的选项。

A. intelligent   B. desire   C. disappointed   D. universe   E. launched   F. data

Mankind has been exploring space to find out the secret of the     1     and has     2     a lot of satellites into space, which can transmit     3     to scientists on earth. However, exploring space is dangerous and challenging. These disasters made everyone     4    , but the     5     to explore the universe never end.

【推荐3】Directions: After reading the passage below, fill in each blank with a proper word given in the box. Each word can only be used once. Note that there is one word more than you need.

A. advances               B. colonize               C. concerns               D. eventually            E. extremely F. face                      G. spread                  H. stop                    I. surface               J. survive   K. visit

Living in Space

Stephen Hawking, one of the world’s most important scientists in history, believed that to survive, humans must move into space: “Once we     1    out into space and establish independent colonies, our future should be safe,” he once said.

Today, the European Union, India, China, Russia, and Japan are all planning to send astronauts back to the earth’s closest neighbor: the moon. Some of these countries want to create space stations there between 2020 and 2030. These stations will prepare humans to     2    and later live on Mars or other earthlike planets.

Robert Zubrin, a rocket scientist, thinks humans should     3    space. He wants to start with Mars. Why? He thinks sending people to Mars will allow us to learn a lot — for example, about the ability of humans to live in a very different environment. Then we can     4    create new human societies on other planets. In addition, any     5     we make in the fields of science, technology, medicine, and health will also benefit us here on the earth.

However, not everyone thinks sending humans into space is a smart idea. Many say it’s too expensive, even if it’s just a short journey. A one-way trip to Mars, for example, would take about six months. People travelling this kind of distance     6    many health problems. Also, these first people would find life     7    difficult out in space. On the moon’s     8    , for example, the sun’s rays are very dangerous. People would have to stay indoors most of the time.

Despite these     9    , sending people into space seems certain. In the future, we might see lunar cities or even new human cultures on other planets. First     10    : the moon.

【推荐2】Directions: Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.

A. targeted. B. questions C. abnormally D. concerned E. reduces F. outlet G. intake H. correctly I contrary J. recommended K. moderation

Low-salt diets are actually harmful to our bodies, a recent study found. These diets may actually increase the risk of developing heart disease, or even cause death. These findings, says WebMD, a public health website, are     1     to the popular wisdom that has long said low-salt diets are healthy.

The scientists, led by Andrew Mente of McMaster University, wanted to find out if the relationship between salt, strokes and heart disease is different for those who have high blood pressure. They found that whether one has high blood pressure or not, low sodium     2     increased the risk of stroke, heart attack and death.

The study goes on to suggest that only certain people should be     3     about reducing sodium in their diets. “The findings emphasize the importance of reducing salt intake among people with hypertension and who eat food with high levels of sodium,” Mente said. McMaster University’s Martin O’Donnell said, “This study adds to our understanding of the relationship between salt intake and health. The study also     4     the correctness of present guidelines that recommend low salt intake for everyone.”

He noted, “An approach that recommends salt in     5    , particularly focused on those with hypertension, appears more in-line with current evidence.” Mente added that the current general recommendations relating to the maximum healthy salt intake seems too low, especially since they do not consider an individual’s blood pressure.

Low sodium intake reduces blood pressure modestly, compared to average intake, but low sodium intake also has other effects. “One of those effects includes harmful elevation of particular hormones — and this     6     many benefits. The main issue is not whether very low sodium intake lowers blood pressure, but whether it results in improved health,” Mente said. In general, health experts consider a high level of sodium consumption to be over 6 grams daily. Mente pointed out that this indicates that many people around the world are taking in healthy amounts of salt. He also said that efforts should be    7     at reducing salt intake among the people who are most likely to get hypertension and who take in high amounts of salt. Mente does not agree with the current strategy of reducing sodium intake in almost all countries. However, he would accept efforts to reduce salt intake in some areas, such as China or Central Asia, where the average salt consumption is     8     high.

In Kenya, the Ministry of Public Health and Sanitation recommends general reduction of salt intake to levels below 5 grams as     9     by the World Health Organization. Less than 5% of people in the world consume such low levels of sodium. The WebMD report says Elliott Antman, past president of the American Heart Association (AHA) criticized Mente’s study. Antman says the study does not     10     measure sodium intake, and it should not make Americans stop worrying about salt. The American Heart Association continues to recommend less than 1.5 grams of sodium per day from all sources, he said.