When a laptop or smartphone battery starts losing its power, the only options are to buy an expensive replacement or just keep it plugged in all the time. But a woman Mya Le Thai may have found the solution to this problem.
Thai was frustrated that the batteries for her wireless devices degraded (退化) over time, until they failed to charge fully. She did not like having to keep her laptop connected to an electrical outlet to keep it powered on. So, she decided to do something about that problem. At first, she and her team at UC Irvine thought about inventing a new battery. But as they experimented, Thai discovered something that might permit lithium-ion (锂离子) batteries to last forever.
Lithium-ion batteries power most wireless devices. Over time, the batteries lose the ability to hold a charge. Most of these batteries have a lifespan of about 7,000 charging cycles before they die. One of the reasons lithium-ion batteries degrade is their use of nanowires to carry electricity. Nano wires are extremely thin. A human hair is thousands of times thicker, for example. Nano wires are extremely efficient carriers of electricity, which makes them useful in batteries.
But, Thai had a theory — the nanowires might last longer if covered with a gel (凝胶). She and her team tested this theory. “It was a long process and a lot of work,” Thai said. The team tried many coverings for the wires. PMMA, a type of plastic, was one of them. The nanowires were coated with PMMA and cycled through charging 200,000 times. The PMMA-coated nanowires showed no evidence of damage. The results suggest that batteries could last forever without losing charging ability.
Thai hopes to continue her research to understand why this gel works so well and to see if any other gel could create better results and she is enjoying the publicity about her discovery. She said she never expected her research to get media coverage. “It’s kind of cool,” she said. “I’m really glad people are showing interest in my work and not just in the work itself; but also in technology and energy.”
1.Why did Mya Le Thai work on lithium-ion batteries?
A.She disliked the batteries for her laptop.
B.Her team were ordered to invent a new battery.
C.Many people thought batteries were too expensive.
D.The batteries would soon fail to get fully charged.
2.What can we infer about nanowires?
A.They are too weak to carry electricity.
B.They are not suitable to use in batteries.
C.They Iasi exactly 7,000 charging cycles.
D.Their thinness is a cause of batteries degrading.
3.What was Thai and her team’s breakthrough?
A.Coating nanowires in a gel. B.A new kind of battery.
C.New materials for batteries. D.A new way of charging batteries.
4.What may be the best title for the passage?
A.Mya Le Thai discovered nanowires B.A woman invents a lasting battery
C.The options of batteries for wireless devices D.The reasons for batteries degrading
Sleepiness and boredom lead to yawning (打哈欠), so it has long been believed that the action makes us feel more awake by stretching the muscles surrounding the lungs, or by bringing more oxygen to the blood and the brain. Yet in tests, breathing air with high levels of carbon dioxide or even pure oxygen made no difference to the frequency of yawns.
Another theory, proposed by the French physician Olivier, is that yawning improves the circulation of the fluid (液体) that surrounds the brain. As a result, we can focus better on a task. This might explain why athletes often yawn naturally before they compete.
Recently, though, a new explanation has appeared: Yawning is a way to cool the brain. Experiments led by Gordon Gallup at the University at Albany showed that people yawned far less when their head was cooled by a cold pack compared with holding a heated pack to their forehead The temperature of the brain rises when we are tired, so it is possible that yawning is a way to protect the brain from overheating due to tiredness.
But a strange thing is that when we see another person yawn, we catch it too. In other words, yawning is contagious.
How can we make sense of these different types of yawning? It’s possible that contagious yawning is something different, and might have a social purpose. Steven Palek and his colleagues at the University at Albany say that contagious yawning may be linked to our ability to understand what others want to do. If you are good at reading others’ facial expressions you are more likely to “catch” a yawn. Therefore, lonely people tend to be less affected by yawing, according to research by Atsushi Senju, now at Birkbeck, University of London.
So the simple act of yawning tursout to be surprisingly complex Has this research made you yawn yet?
1.Based on the theory of Olivier, yawning ________.
A.is caused by lack of sleep
B.contributes to concentration
C.is a way to bring more oxygen to the blood
D.increases the circulation of the fluid in lungs
2.The underlined word “contagious” in Paragraph 4 is closest in meaning to _________.
A.Infectious B.Influential
C. Attractive D.Comfortable
3.How is the passage mainly developed?
A.By making comparisons.
B.By listing different figures.
C.By providing explanations.
D.By telling personal experiences.
Deciding to get her money’s worth out of the wedding dress on which she spent over $1,000, an Australian woman has been wearing her wedding dress, a year after her wedding.
43-year-old Tammy Hall adopted a new lifestyle—anti-consumerism (反消费主义) lifestyle in 2016, after a trip to India opened her eyes to how much we as a society consumed. She decided not to buy any new clothes or footwear for a whole year after she returned home to Adelaide, in Southern Australia, and she managed to make it.
But last year, as her wedding day approached, she faced a dilemma. She wanted to look good on the most important day of her life, but how could she spend a small fortune on the wedding dress she would only wear on that day?
“In the end I decided that if I was going to get a wedding dress, I’d make sure I could get my money’s worth,” Hall tells PA Real Life.
“The first time I wore it after the wedding was to vote in the Australian election in early 2019,” the 43-year-old adds. “Since then, it’s been to all sorts of places. Wearing it on a crowded train was especially funny, but I’ve worn it to do housework, to football games and to the gym.”
Hall says that she has got some strange looks from people, but no irritating comments. It may have something to do with the fact that the dress is not the fanciest, but she believes people are just too reserved to say anything. Anyway, she doesn’t really care, because she knows she has to hit the goal she has set and wearing the dress multiple times is the most reasonable way she could think of to make the most of her wedding dress.
Hall now plans to wear her wedding dress on a trip to Iceland that she and her partner will take nest summer.
1.Why did Tammy Hall adopt a new lifestyle?
A.To adapt herself to Indian life. B.To save money for her next trip.
C.To cut down her consumption. D.To get prepared for her wedding.
2.What did Tammy Hall do to get her money’s worth out of her wedding dress?
A.She brought fun to people with it B.She wore it repeatedly in daily life.
C.She tried to wear it to earn money. D.She got it exchanged again and again
3.What can we infer about Tammy Hall?
A.She has been struggling to make ends meet.
B.She has influenced people’s lifestyle widely.
C.She values her wedding dress less than her trips.
D.She is determined to turn her ideas into practice.
The little boy with big brown eyes was waiting for us on the other side of the world. Ever since our adoption agency had _________ us, I’d been hurriedly _________ all the necessary paperwork. I made it a personal goal to never _________ the process. On one late afternoon in June. I rushed toward the closest FedEx office. I had some _________ to send overnight, and I wanted them to go out that day.
I thought I knew _________ the FedEx office was. I drove there as the minutes slipped away, only to find that the office was no longer _________ where I remembered it. Tears came to my eyes. This was _________ we all had a smartphone in our pockets. I had no way of _________ the correct location. _________ , I started driving toward home. I felt like a failure, as though I’d just __________ my new son to more days in an orphanage waiting for us.
Suddenly, I was __________ at a stoplight by an oversized box truck My anger turned to __________ when I saw the sign. It was a FedEx truck I __________ closely behind the truck. What were the __________ the truck would lead me straight to the FedEx office I was seeking?
It __________ the chances were good. Less than five minutes later, I saw a FedEx sign, and the truck made a turn into the parking lot. I had __________ in my eyes again.
Our documents went out that night. The truck driver __________ knew he was an angel for me that day. Three months later, we flew halfway around the world to __________ our son for the first time. We have been with him every day since.
Miracles are always around us __________ we are open to them. Sometimes, it’s a smile at the right time or a kind word. And every now and then, it’s even a big __________ that cuts us off in traffic.
1.A.debated B.challenged C.matched D.scanned
2.A.hiding B.completing C.evaluating D.underlining
3.A.delay B.start C.repeat D.simplify
4.A.gifts B.letters C.documents D.postcards
5.A.how B.what C.which D.where
6.A.locked B.located C.ranked D.repaired
7.A.before B.after C.since D.when
8.A.finding B.choosing C.describing D.showing
9.A.Bored B.Delighted C.Disappointed D.Surprised
10.A.compared B.sentenced C.appointed D.accompanied
11.A.kept up B.put down C.taken in D.cut off
12.A.guilt B.panic C.shock D.terror
13.A.ran B.arose C.walked D.followed
14.A.chances B.wonders C.doubts D.promises
15.A.turned off B.turned out C.broke off D.broke out
16.A.dust B.dirt C.tears D.sands
17.A.just B.never C.exactly D.immediately
18.A.free B.meet C.beat D.spoil
19.A.if B.although C.unless D.until
20.A.tree B.lie C.smile D.truck
His story of what happened that night didn’t ________ the witness’s version.
A.try out B.put off C.speed up D.correspond with
I think it is important for children to have brothers and sisters they can ________.
A.relate to B.split up C.drop off D.decide on
