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 . Over the past two weeks, I've lost my passport, barked at a neighbor and published a picture of myself wearing a kid's superhero costume. Forgetfulness, anger and poor decision-making are all signs of sleep shortage.
And I'm not alone.
“I average around six hours a night,” admits Paul, who's lived in Shanghai for three years. “But how much of that is deep sleep, I don't know.”
Lisa works in a hotel. “I struggle to switch off,” she says, “a glass of red wine with dinner helps.”
March 21 is the World Sleep Day, an annual event in celebration of slumber, or sleep. When sleep problems become a global epidemic, it's time to ask: “Am I getting enough?”
The lack of sleep throughout industrialized nations is damaging our health, wellness and safety. We're dog-tired, the impact of which is enough to keep anyone up at night.
A global experiment is performed on 1.6 billion people across 70 countries twice a year: daylight savings. When one hour of sleep is lost in spring, there's a 24 percent increase in heart attacks, and in autumn, when the hour is regained, a 21 percent reduction.
Good sleep increases concentration, attention and decision-making. Creativity goes up, and our ability to find novel solutions to complex problems is hugely improved. Sleep reduces mood swings and stress levels. We drink less alcohol and make better food choices when rested.
Take sleep seriously. It's not a luxury, but a biological necessity. It's our life-support system and let it be our superpower.
1. Why does the author mention his own experiences in Paragraph 1?| A．To draw attention to his situation. | B．To complain about lacking sleep. |
| C．To introduce the topic of the text. | D．To raise a question about deep sleep. |
| A．Turn off. | B．Disinterest someone. | C．Stop talking. | D．Fall asleep. |
| A．The loss of sleep increases the risk of heart attacks. |
| B．Short sleep is linked to mental health problems. |
| C．Good sleep leads to better work performances. |
| D．Red wine is effective in treating sleeplessness. |
| A．Celebrating the World Sleep Day. | B．Paying attention to sleep problems. |
| C．Getting six hours' sleep every day. | D．Taking sleeping pills when necessary. |
