1 . Until now, scientists haven’t been able to study the new rock on the moon.The new samples from Chang’e 5 will change this. They’re from near Mons Rümker, a volcanic mountain where the rock is thought to be much younger-- about 1 billion years old.
There are a lot of reasons scientists are eager to study this younger rock, one of which is that it could help us more precisely date not only the moon, but many rocky planets and other objects.
Here’s how that works: Scientists date lunar rock by using something called a chronology curve（年代学曲线）, says Jollliff, a scientists at Washington University in St. Louis. Basically, they estimate the age of the rock by counting the number of craters（火山口） in the area the rock comes from; those increase as objects strike the rock over time. To make this estimation, scientists need to match the number of craters to a precise age. Right now, they only have data points for lunar rock that is 3 to billion years old. Modern techniques can date the new sample extremely accurately, and once scientists know its precise age, they can add a valuable data point to their chronology curve. The dating system will also help us more accurately estimate the age of all sorts of objects in space, like rocky planets and other moons.
Another reason scientists are keen to study this young volcanic rock is to find out more about how volcanism works on the moon. Jollliff says that it’s unclear why there was volcanic activity on the moon for such a long period of time. Most of the moon; s volcanic activity, he says, is thought to have occurred 3 or 4 billion years ago, when the moon was still pretty young. But since the moon does not have plate structure, which drives volcanism on Earth, it’s unclear what could have caused much later volcanic activity. “That’s something that you can find out of the samples by studying them in the lab,” Jollliff says.
1. What does the underlined word “this” in paragraph 1 refer to?| A．The fact of being unable to study the new rock. |
| B．The new rock from near Mons Rümker. |
| C．One of the reasons to study the moon;s new rock. |
| D．The study of the moon’s younger rock. |
| A．ensure there was volcanic activity on the moon. |
| B．more precisely date only the moon. |
| C．date lunar rock by using a chronology curve. |
| D．explore how volcanism works on the moon. |
| A．Scientistsare keen to study this young volcanic rock. |
| B．Scientists can’t know why volcanic activity exists on the moon. |
| C．The moon’s volcanic activity occurred 3 or 4 billion years ago. |
| D．It’s clear what could have caused much later volcanic activity. |
| A．How scientists study the younger rock. |
| B．Why the research is important. |
| C．Why the younger rock is worth studying. |
| D．What scientists do to study the younger rock. |
2 . Japanese officials say they are pleased with the quality of the asteroid (小行星) material collected by a spacecraft and returned to Earth.
Last week, officials from Japan described the samples (样品), which were collected from the Ryugu asteroid in July 2019. Ryugu sits more than 300 million kilometers from Earth. Japan’s unpiloted Hayabusa2 spacecraft removed the material after making a hole into the asteroid.
The space agency said the July 2019 mission (任务) aimed to collect samples from below the surface of Ryugu. During an earlier operation in February 2019, Hayabusa2 collected material from a different part of the asteroid. The second collection effort resulted in sample pieces as big as 1 centimeter. The black material looked similar to charcoal and was very hard. It did not break apart when picked up or poured into another container.
Earlier this month, space officials described the samples Hayabusa2 removed on its first mission as smaller, sandy pieces. They were collected from the surface of Ryugu. Hayabusa2 was launched in December 2014 and arived near Ryugu in June 2018. The Japanese space mission aims to use the samples to learn more about how our solar system formed.
To get the second set of samples in July, Hayabusa2 used an impactor to knock the asteroid’s surface. The aim was to collect material unaffected by space radiation or other environmental conditions. The size differences suggest different hardness of the bedrock of the asteroid. One possibility is that the place of the second touchdown was a hard bedrock and larger particles broke and entered the container.
Hayabusa2 is now on another mission to a smaller asteroid, called 1998KY26. The Japanese government expects the aircraft to take 11 years to reach that asteroid. Hayabusa2’s new mission aims to study possible ways to prevent large meteorites (陨石) from hitting Earth.
1. What are these asteroid materials used to do?| A．Study how the solar system was born. | B．Determine the movement of asteroids. |
| C．Study the environment on the asteroid. | D．Uncover when the asteroid was formed. |
| A．To discover new planets. | B．To fetch more materials in space. |
| C．To travel around the solar system. | D．To explore ways to protect the earth. |
| A．They were collected in the same place. | B．They both were black and hard. |
| C．They came in different shapes. | D．They were of equal weight. |
| A．Japan Makes Progress in Studying Solar System |
| B．Japan Is Pleased with Latest Asteroid Samples |
| C．The Secret of an Asteroid Comes to Light |
| D．The Earth Faces Threats from Space |
3 . Humans are not the only ones who underwent self-domestication. So did our close relatives, the bonobos, and the species we call our best friend. A tiny proportion of the genome differentiates dogs from wolves, and yet millions of dogs are comfortably curled up in our homes, while wolves move around at the edge of extinction.
When our research group began its work almost 20 years ago, we discovered that dogs also have extraordinary intelligence: they can read our gestures better than any other species. Wolves, in contrast, are mysterious and unpredictable. Their home is the wilderness, and that wilderness is shrinking.
But not so long ago the evolutionary race between dogs and wolves was so close, it was unclear who would win. Dogs, in fact, did not descend from wolves. Instead, dogs and wolves shared a wolflike ancestor.
Folklore supposes that humans brought wolf puppies into camp and domesticated them. Or as wolf expert David Mech wrote in 1974, “Evidently early humans tamed wolves and domesticated them, eventually selectively breeding them and finally developing the domestic dog from them.” But this story has not held up. Taming an animal occurs during its lifetime. Domestication happens over generations and involves changes to the genome.
So how did wolves turn into dogs? Back in the Ice Age, as our human populations grew more sedentary, we probably created more rubbish, which we then dumped outside our camps. These leavings would have included tempting pieces of food for hungry wolves. Not every wolf would have been able to scavenge, however. These animals would have had to be unafraid of humans, and if they displayed any aggression toward us, they would have been killed. After generations of selection for friendliness without intentional selection by humans, this special population of wolves would have begun to take on a different appearance. Coat color, ears, tails: all probably started to change.
Animals that could respond to our gestures and voices would be extremely useful as hunting partners and guards. They would have been valuable as well for their warmth and companionship, and slowly we would have allowed them to move from outside our camps to our firesides. We did not domesticate dogs. The friendliest wolves domesticated themselves.
1. What can be summarized about wolves and dogs from the first three paragraphs?| A．Wolves are smarter than dogs. |
| B．They are very much racially divided. |
| C．They are close relatives but dogs seem to be on the winning side. |
| D．Dogs have made their ways to indoor life while wolves to the wild. |
| A．diverse | B．limited |
| C．living in the same place | D．involving regular migration |
| A．Dogs evolved from wolves. |
| B．Selective breeding developed domestic dogs. |
| C．Taming and domesticating an animal are the same thing. |
| D．Friendliness as a quality translates into an evolutionary strategy. |
| A．From Wolf to Dog | B．Dog: Our Favorite Pet |
| C．An Intentional Domestication | D．A Competition Story between Wolf and Dog |
