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  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 , 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   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 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
B
------
Almost every day, we discuss the topic of health, especially for kids. But what is health? "Health" means eating well, getting enough exercise, and having a healthy weight. Let's read the following rules. They can help you stay healthy. 1 Eat _ foods, especially fruit and vegetables. We all know that eating fruit and vegetables can help us stay healthy, but many of us only eat our favorite foods. Remember that we can only get the nutrition  we need by eating different kinds of food, especially fruit and vegetables. 2 Drink water and milk most often. Everyone knows that water is important. Besides that, kids need plenty of calcium  to grow strong bones, and milk has a lot of it. Every day, you should drink at least three cups of milk (1300 milligrams of calcium), when you are 9 years old or older. You should also try to have less sugary drinks, like soda and coca. They include a lot of sugar. Sugar just includes calories, not important nutrition. 3 Listen to your body. When you are eating, notice how your body feels. When your stomach feels comfortably full, stop eating. Eating too much makes you feel uncomfortable. If you do it too often, it can make you unhealthy and fat. 4 Limit  screen time. What's screen time? It's the amount of time you spend watching TV, movies, and playing computer games. The more time you spend on these sitting-down activities, the less time you spend playing sports, like basketball, and doing other activities like bike riding and swimming. Try to spend no more than 2 hours a day on screen time. What's the main idea of the passage? A) How to eat healthily. B) Eating and playing are both important. C) Advice for staying healthy. D) Health is very important.
C
------
A team of British surgeons has carried out Gaza's first organ transplants for a long-term plan to train local medical staff to perform the operations. Two patients underwent kidney transplants at the Shifa, Gaza's biggest public hospital. The operations were conducted a fortnight ago by a volunteer medical team from the Royal Liverpool hospital. Ziad Matouk, 42, was born with one kidney and was diagnosed with renal failure several years ago. Matouk, whose wife donated one of her kidneys, hopes to return to his job within six months. The couple had sought a transplant in Cairo, but were rejected as unsuitable at a state hospital and could not afford the fee at a private hospital. "We were desperate," said Matouk. The UK-Gaza link-up began about a year ago after Abdelkader Hammad, a doctor at the Royal Liverpool hospital, was contacted by an anaesthetist at the Shifa, who outlined the difficulties the Gaza hospital was facing with dialysis . The Shifa is forced to rely on generators because of power cuts; spare parts for its ageing dialysis machines have been difficult to import; and supplies of consumables are often scarce. After an exploratory trip last April, Hammad---whose family is Palestinian---and three colleagues from Liverpool arrived in Gaza via Egypt last month, bringing specialist equipment. Two patients were selected for surgery. The first, Mohammed Duhair, 42, received a kidney donated by his younger brother in a six-hour operation. Two days later, Matouk received a transplant after his wife, Nadia, 36, was found to be a good match. The surgeon was carried out by the British team, assisted by doctors and nurses from the Shifa. "We are very satisfied with the results," said Sobbi Skaik, head of surgery at the Gaza hospital. Skaik hopes that Gaza medical teams will eventually carry out kidney transplants independently, and that other organ transplants may follow. The Shifa is working with the Gaza ministry of health on a plan to train its doctors, surgeons, nursing staff and laboratory technicians... What did Dr. Hammad and his team do recently? A) They had an exploratory trip in Egypt last April. B) They carried out surgeries to test Gaza's medical equipment. C) They carried out two transplant surgeries in Gaza. D) They sought assistance from the hospital of the Shifa.

C
------