China has become the first country to land a spacecraft on the far side of the moon. The unmanned Chang’e-4 probe (探测器) - the name was inspired by an ancient Chinese moon goddess     1     (touch) down last week in the South Pole-Aitken basin. Landing on the moon’s far side is     2     (extreme) challenging. Because the moon’s body blocks direct radio communication with a probe, China first had to put a satellite in orbit above the moon in a spot     3     it could send signals to the spacecraft and to Earth. The far side of the moon is of particular     4     (interesting) to scientists because it has a lot of deep craters (环形山)， more so     5     the familiar near side. Chinese researchers hope to use the instruments onboard Chang’e-4     6     (find) and study areas of the South Pole-Aitken basin. ＂This really excites scientists,＂ Carle Pieters, a scientist at Brown University, says, ＂because it     7     (mean) we have the chance to obtain information about how the moon     8     (construct)＂ Data about the moon’s composition, such as how     9     ice and other treasures it contains, could help China decide whether     10     (it) plans for a future lunar (月球的) base are practical.

In ancient China lived an artist    1     paintings were almost lifelike. The artist’s reputation had made him proud. One day the emperor wanted to get his portrait (画像) done so he called all great artists to come and present their     2     (fine) work, so that he could choose the best. The artist was sure he would    3    (choose), but when he presented his masterpiece to the emperor’s chief minister, the old man laughed. The wise old man told him to travel to the Li River～perhaps he could learn a little from the greatest artist in the world.

Filled with     4     (curious), the artist packed his bags and left.     5     he asked the villagers on the banks of the river where he could find the legendary (传奇的) artist, they smiled and     6     (point) down the river. The next morning he hired a boat and set out     7     (find) the well-known painter. As the small boat moved,     8     (gentle) along the river he was left speechless by the mountains being silently reflected in the water. He passed milky white waterfalls and mountains in many shades of blue. And when he saw the mists rising from the river and the soft clouds    9     (surround) the mountain tops, he was reduced to tears. The artist was finally humbled (谦卑) by the greatest artist     10     earth, Mother Nature.

In a study of 33 years of trends in Body Mass Index (体重指数) across 200 countries, the scientists found that people worldwide are getting heavier     1     that most of the rise is due to gains in BMI in rural areas.

BMI is an internationally recognized measurement tool     2     gives an indication of whether someone is a healthy weight. It is calculated by dividing a     3     (person) weight in kg by their height in meters squared. and a BMI of between 19 and 25     4     (consider) healthy.

The study found that between 1985 and 2017, average rural BMI increased     5     2. 1 in women and men. In cities, however, the gain     6     (be) 1. 3 in women and 1. 6 in men. The researchers described “striking changes” in the geography of BMI. Tn 1985，urban men and women in more than three quarters of the countries     7     (study) had higher BMIs than men and women in rural areas. But 30 years later, the BMI difference between urban and rural people in many countries had narrowed     8    (sharp).

This may be due to some disadvantages for people     9     (live) in the countryside, including     10     (low) levels of income and education, higher costs of healthy foods, and fewer sports facilities.

The polar bear is found in the Arctic Circle and some big land masses as far south as Newfoundland. While they are rare north of 88°, there is evidence     1     they range all the way across the Arctic, and as far south as James Bay in Canada. It is difficult to figure out a global population of polar bears as much of the range has been     2    (poor) studied; however, biologists calculate that there are about 20,000-25,000 polar bears worldwide.

Modern methods     3     tracking polar bear populations have been employed only since the mid-1980s, and are expensive     4    (perform) consistently over a large area. In recent years some Inuit people in Nunavut     5    (report) increases in bear sightings around human settlements, leading to a     6    (believe) that populations are increasing. Scientists have responded by     7    (note) that hungry bears may be congregating(聚集) around human settlements, leading to the illusion(错觉) that populations are     8    (high) than they actually are. Of     9     nineteen recognized polar bear subpopulations, three are declining, six     10    (be) stable, one is increasing, and nine lack enough data.

Many people have the hobby of collecting things, e.g. stamps, postcards or antiques. In the 18th and 19th centuries,     1     (wealth) people travelled and collected plants, historical objects and works of art. They kept their collection at home until it got too big     2     until they died, and then it was given to a museum. The 80,000 objects collected by Sir Hans Sloane, for example,     3     (form) the core collection of the British Museum     4     opened in 1759.

The parts of a museum open to the public     5     (call) galleries or rooms. Often, only a small part of a museum’s collection     6     (be) on display. Most of it is stored away or used for research.

Many museums are lively places and they attract a lot of visitors. As well as looking at exhibits, visitors can play with computer simulations (模拟) and imagine     7     (they) living at a different time in history or     8    (walk)through a rainforest. At the Jorvik Centre in York, the city’s Viking settlement is recreated, and people experience the sights, sounds and smells of the old town. Historical     9     (accurate) is important but so is entertainment. Museums must compete     10    people’s spare time and money with other amusements. Most museums also welcome school groups and arrange special activities for children.