The relationship between exercise and cancer has long both intrigued and puzzled oncologists and exercise physiologists.
Exercise is strongly associated with lowered risks for many types of cancer. At the same time, exercise involves biological stress, which typically leads to a short-term increase in inflammation(发炎)which can contribute to higher risks for many cancers.
Now, a new study in mice may offer some clues into the exercise-cancer paradox. It suggests that exercise may change how the immune system deals with cancer by boosting adrenaline(肾上腺素), certain immune cells and other chemicals that, together, can reduce the severity of cancer or fight it off altogether.
To try to better understand how exercise can both elevate inflammation and simultaneously protect the body against cancer, scientists at the University of Copenhagen in Denmark and other institutions decided to closely examine what happens inside mice at high risk for the disease.
So, for the new study, they began by gathering a group of adult lab mice. These animals generally like to run.
The scientists then implanted melanoma (黑素瘤) skin cancer cells into the mice before providing half of them with running wheels in their cages while the other animals remained sedentary. After four weeks, far fewer of the runners had developed full-blown melanoma than the sedentary mice and those that had been diagnosed with the disease showed fewer and smaller lesions.
They drew blood from both the exercising and sedentary animals and cells from any tumors in both groups. As expected, they found much higher levels of the hormone adrenaline in the blood of the exercising animals, especially right after they had been working out on the wheels but also at other times of the day. The body releases adrenaline in response to almost any type of stressful experience, including exercise.
They also found higher levels of interleukin-6 in the blood of the runners. This is a substance that is released by working muscles and is believed to both increase and decrease inflammation in the body, depending on where and how it goes to work.
Perhaps most important, they found much higher numbers in the bloodstreams of runners than in the sedentary mice of a type of immune cell named natural killer cells that are known to be strong cancer fighters.
So the scientists repeated their original experiment multiple times, inducing cancer while allowing some mice to run and others to sit. In some of these follow-up experiments, the scientists injected the runners with a substance that blocked the production of adrenaline and gave sedentary animals large doses of added adrenaline.
What they now found was that when running mice could not produce adrenaline, they developed cancer at the same rate as the sedentary animals, while the sedentary animals that had been injected with extra adrenaline fought off their tumors better than other sitting mice.
More remarkably, the scientists determined that adrenaline seemed to be sending biochemical signals to some of the animals’ IL-6 cells, making them physiologically more alert, so that when a tumor began to develop in the affected animal, those IL-6 cells in turn activated the natural killer cells in the bloodstream and actually directed them to the tumors, like minute guide fish.
With these results, “we show that voluntary wheel running in mice can reduce the growth of tumors, and we have identified an exercise-dependent mobilization of natural killer cells as the underlying cause of this protection,” said Pernille Hojman, a researcher at the University of Copenhagen who oversaw the new study. It perhaps provides one more incentive for us to get up and move.
1.The relationship between exercise and cancer has long puzzled oncologists and exercise physiologists because ________.
A. exercise is strongly associated with lowered risks for many types of cancer
B. exercise can both elevate inflammation for many cancers and protect the body against cancer
C. exercise may change can reduce the severity of cancer or fight it off altogether
D. exercise can increase in inflammation which can contribute to elevated risks for many cancers
2.In the first experiment, which one is the most important result the scientists found?
A. Natural killer cells are much more in the bloodstreams of runners than in the sedentary mice.
B. Levels of interleukin-6 are higher in the blood of the runners than in the sedentary mice.
C. Exercise such as running seemed to help the mice fight against the cancer.
D. Adrenaline can reduce the severity of cancer or fight it off.
3.What does the underlined word “sedentary” mean?
A. run B. move C. sit D. sleep
4.In the follow-up experiments, the scientists found __________.
A. the hormone adrenaline has much higher levels in the blood of the exercising animals
B. how these elements in the runners — their increased adrenaline, IL-6, and natural killer immune cells — fight against tumor
C. interleukin-6 can both increase and decrease inflammation in the body, depending on where and how it goes to work
D. what happens inside mice at high risk for the disease that kill the immune cells
5.According to the study, we can infer the fundamental substance to fight the cancer off is ________.
A. adrenaline B. interleukin-6 C. natural killer cells D. genes
These young men were a different kind of prisoner from those we had seen before. They were brave, hostile and aggressive they would not take orders, and shouted “Amandla！” at every opportunity. Their instinct was to confront rather than cooperate. The authorities① did not know how to handle them, and they turned the island upside down. During the Rivonia Trial, I remarked to a security policeman that if the government did not reform itself, the freedom fighters who would take our place② would some day make the authorities miss us. That day had indeed come on Robben Island.
In these young men we saw the angry revolutionary spirit of the times. I had had some warning. On a visit with Winnie a few months before, she had managed to tell me through our coded conversation that there was a rising class of discontented youths③ who were violent and Africanist in beliefs. She said they were changing the nature of the struggle and that I should be aware of them.
The new prisoners were shocked by what they considered the inhuman conditions of the island, and said that they could not understand how we could live in such a way. We told them that they should have seen the island in 1964. But they were almost as sceptical of us as they were of the authorities. They chose to ignore our calls for discipline and thought our advice weak and unassertive (不果断).
It was obvious that they regarded us, the Rivonia Trialists④, as moderates⑤. After so many years of being branded a radical revolutionary, to be seen as a moderate was a novel and not altogether pleasant feeling. I knew that I could react in one of two ways: I could scold them for their disrespect or I could listen to what they were saying. I chose the latter.
Then some of these men, such as Strini Moodley of the South African Students Organization and Saths Cooper of the Black People’s Convention, came into our section, _________.
Shortly after their arrival on the island, the commanding officer came and asked me as a favour to address the young men. He wanted me to tell them to behave themselves, to recognize the fact that they were in prison and to accept the discipline of prison life. I told him that I was not prepared to do that. Under the circumstances, they would have regarded me as a follower of the authorities.
(---adapted from “Long walk to freedom: The autobiography of Nelson Mandela”)
1.We may infer from the passage all of the following EXCEPT that ___________.
A. an angry massive revolution was probably on its way
B. these young men were willing to cooperate in face of difficulties
C. many were concerned about the influence these young men could make
D. the author’s activities were strictly monitored
2.One sentence is missing in the blank of the passage regarding the author’s following reactions.Which of the following reactions do you think he would have?
A. I tried to calm them down and talked them into behaving.
B. I reported to the officers about their dissatisfaction.
C. I asked them to tell us about their movement and beliefs.
D. I just turned a deaf ear to the young men.
3.Several phrases have been underlined and numbered in the passage; which two of them actually refer to the same people?
A. ①② B. ②③ C. ③④ D. ⑤①
The traditional news media in America has been having a rough time in the last few years. According to a recent survey, more Americans have a negative (43%) than a positive (33%) view of the news media, and are finding it harder to be well informed because it is getting harder to determine which news is accurate.
The problem is preference. While ideally the media should be objective and hold power to account, in reality we know that most news outlets belong to a certain party and have their own agenda to advance. Whether state-owned or run by some shady tax-avoiding billionaire, getting “the masses” to view the world from a certain perspective has always been a priceless power to wield.
So why is trust in the media so low? Well, according to the same survey, 8 out of 10 Americans believe that the news media are critical to their democracy. The gap between these noble expectations of an honest, objective media and the performance that they actually deliver is large. Times when the mask slips and examples of media manipulation(操纵)are exposed are hugely damaging to trust, and people naturally turn to social media for others, even-easier-to-manipulate sources. Thus we are in the current state in which we find ourselves:confused and mistrustful.
People have been posting examples of how media can use different techniques of deception, to trick you into seeing exactly what they wanted you to see. As you will discover, perspective really is everything! It will goes to show that a healthy dose of skepticism goes a long way, and getting your news from a wide range of different sources is your best bet to a more rounded view of the world we live in. Social media is good in that respect, but bad in terms of regulation, trolling and people shouting horrible things at each other. The good old traditional news media really is needed as a forum for reasonable debate and expert opinion, but they gotta stop with the manipulation already!
1.What does para2 want to convey?
A. People have prejudice for media
B. The media can take control of the party
C. The media have acted as a tool to mask the truth
D. The media have a priceless power
2.What’s your understanding of the sentence “As you will discover, perspective really is everything!”?
A. People should not have faith in what the media says because some news are not true.
B. People should not be too curious about things around
C. People should refer to social media rather than traditional media if wanting to know the truth of news.
D. The spirit of suspect and diverse sources are good ways to help people recognize the truth of the world.
3.What’ s the structure of the passage?
A. ①→②③→④ B. ①→②③④
C. ①②③→④ D. ①②→③→④
4.What’ the best title for the passage?
A. Where’s trust in the media.
B. Why people’s trust in the media falls.
C. How people treat trust in the media.
D. What’ s trust in the media
A few things to consider before booking a flight
With fuel costs rising and airlines finding more fees to impose on travelers every day, airfare isn’t getting any cheaper. Since you can’t drive to all your dream destinations, flying is the only way to go sometimes and, undeniably, the fastest. Luckily, there are plenty of ways to find the most affordable fares and also avoid paying as many extra charges as possible when you plan ahead.
Getting the best fare
Airlines put out their fare sales on Tuesday morning, making this day the best day to book a flight for less.
Fly during the least popular times
Tuesday, Wednesday and Saturday are the slowest days to fly, which means cheaper deals than the rest of the week. You can also find reduced rates on early morning flights, since many people don’t like to get up before the sun to get to the airport. Earlier boarding times can also considerably cut down your chances of getting bumped(取消已预定的飞机座位)on an overbooked flight or delayed because of other delayed flights or mechanical issues.
Choose your seat later
Some airlines charge you to pick your seat when you book online, adding even more to the bottom line of your ticket cost. If you show up early on your travel day, you can still get suitable seats. Some of the best seats get held back until flight day, unless others are willing to pay extra for them ahead of time, so you still have the chance at one of those.
Fly on holidays
You already know that summer is the most expensive time to fly, and even though most other times are more affordable, the days surrounding holidays can be crazy. Save big if you’re willing to travel on major holidays, such as Thanksgiving and Christmas.
Don’t wait until the last-minute to book
Many travelers don’t know that there’s a sweet spot for booking and getting the best price on your tickets. Book too early or too late and you could end up paying more than you need to. The best time to book is between three months and six weeks from when you want to travel.
Avoiding extra fees
Airlines will charge for just about anything these days. Some have even toyed around with charging customers for using the restroom. All those extra fees can certainly add up, but there’s no reason to pay them if you don’t have to. Here are some tips to keep money in your wallet once you get to the airport.
Avoid the upgrade it's not necessary
Sometimes upgrades are free, but mostly you will be charged for seeking a last-minute bump to first class, and the cost can be large.
Fly carry-on only
Baggage fees vary wildly, but almost all airlines charge them and charge big. Why pay for your clothes to fly with you? If everyone in your travel party checks a bag, your bill can be astronomical before you ever even get to your destination. It’s easy to reduce the amount of stuff you pack: Make sure all your clothing coordinates, so you can take less and still make more outfit combinations, take only two pair of shoes, plan to do a bit of laundry on your trip and bring only travel-sized toiletries.
Pack your own snacks
Unless you’re flying internationally, it’s rare your flight comes with a free meal. Snacks on the plane are not cheap and almost never healthy. Don’t rely on what’s on the small menu and instead tuck some of your own snacks – granola bars, homemade muffins, fruit and trail mix all make fantastic travel foods – into your bag and eat a lot better, and cheaper, than other passengers.
Do you have a tried and true method of getting the best deal on your flights? Let us know.
1.To save money, which one should NOT be the choice?
A. Early morning flights
B. Early boarding times
C. The flights on Saturday
D. The flights on Summer holiday
2.According to the passage, which one is right?
A. If you show up early on your travel day, you can get the best seats.
B. You can save big if you’re willing to travel on Christmas eve.
C. You will be charged for seeking the upgrades, and the cost can be high.
D. If you’re flying internationally, your flight will come with a free meal.
3.According to the passage, you can do the things except _____ to avoid extra fees.
A. use the restroom
B. eat your own snacks heartily
C. fly with carry-on
D. give up the upgrade
Few Americans stay in one place for a lifetime. We ______ from the city to the suburbs，from high school to college in a different state, from a job in one region to a better job ______, from the home where we ______ our children to the home where we plan to live in ______. With each move we are ______ making new friends, who become part of our new life.
For many of us the summer is a special time for forming new ______. Today, millions of Americans go on vocation ______, and they go not only to see new sights but also — in those places where they do not feel too ______ — with the hope of meeting new people. No one really ______ a vacation trip to produce a close friend, but the beginning of a friendship is possible. Surely in every country people ______ friendship？
The word “friend” to American people can be ______ to a wide range of relationships — to someone one has known for a few weeks in a new place, to a close business companion, to a childhood playmate, to a man or woman, to a ______ colleague. There are real ______ among these relations for Americans — a friendship may be ______, casual, situational or deep and lasting. But to a European, who sees only our surface behavior, the differences are not clear.
As Europeans see it, all kinds of “friends” flow ______ of Americans' homes with little ceremony. They may be parents of the children's friends, house guests of neighbors, members of a committee, business associates from another town or even another country. ______ as a guest into an American home, the European visitor finds no ______ differences. The atmosphere is ______. Most people, old and young, are called ______ first names. Americans’ characteristic openness to different styles of relationship makes it possible for us to find new friends abroad with whom we feel ______.
1.A. drive B. commute C. move D. settle
2.A. abroad B. elsewhere C. somewhere D. nowhere
3.A. deliver B. protect C. educate D. raise
4.A. retirement B. death C. illness D. sadness
5.A. mostly B. mainly C. rarely D. forever
6.A. championships B. friendships C. hardships D. leaderships
7.A. along B. freely C. together D. abroad
8.A. alone B. strange C. scared D. remote
9.A. allows B. desires C. expects D. imagines
10.A. form B. develop C. ignore D. value
11.A. used B. applied C. stuck D. dedicated
12.A. kind B. generous C. trusted D. helpful
13.A. differences B. varieties C. distinctions D. diversities
14.A. informal B. reliable C. shallow D. fragile
15.A. in and out B. on and on C. by and by D. up and down
16.A. Moving B. Flowing C. Going D. Coming
17.A. obvious B. heavy C. apparent D. strong
18.A. weird B. stressed C. relaxed D. strange
19.A. with B. on C. for D. by
20.A. at best B. at home C. at heart D. at hand
—— Can I really get a Huawei Cell Phone as a reward if I win the race?
—— Absolutely! ______.
A. I mean it B. So will you C. I beg to differ D. You’ve got me there
