Different vitamins are found in different foods. Then which foods should be eaten to keep us healthy？ Let's look at some important vitamins for the answer. Vitamin A helps to protect skin from becoming dry. It is also helpful to the eyes. Without vitamin A， you cannot see well in darkness. Vitamin A is found in animal liver and yellow part of eggs. Sweet potatoes， carrots and other dark colored fruit and vegetables have something that the body can change into vitamin A. Vitamin B changes foods into energy and helps the heart and nervous system（神经系统）to work smoothly. Without it， we will be weak and will not grow. It is found in grains and other foods like beans， nuts， meat and fish. Vitamin B helps to produce red blood cells. It is found in foods like eggs， meat， fish， milk and green leafy vegetables. Vitamin C is needed for strong bones and teeth， and for healthy blood vessels（血管）. It also helps wounds to heal（愈合）quickly. The body stores little vitamin C， so we must get it in foods like oranges， and cabbage. Vitamin D increases the levels of calcium（钙）in the blood. Calcium is needed for verve（活力）and muscle（肌肉）cells to work normally， as well as to build strong bones. Fish liver oil has vitamin D. In some countries， milk producers add vitamin D to milk so that it will be good for children. （1）Without ____ ， we cannot see well in darkness.A. vitamin BB. vitamin AC. vitamin CD. vitamin D（2）According to the passage， vitamin B can be found in ____ .A. fish liver oilB. grains， meat and fishC. oranges and cabbageD. animal liver and eggs（3）Some milk producers add vitamin D to milk mainly to help children to ____ .A. have good eyesightB. produce blood cellsC. get enough calciumD. heal wounds quickly

For decades, public health officials have puzzled over a surprising fact about HIV: only about 10-20 percent of infants who are breastfed by infected mothers catch the virus. Tests show, though, that HIV is indeed present in breast milk, so these children are exposed to the virus multiple times daily for the first several months of their lives.Now, a group of scientists and doctors from Duke University have figured out why these babies don’t get infected. Human breast milk naturally contains a protein called Tenascin C that neutralizes HIV and, in most cases, prevents it from being passed from mother to child. Eventually, they say, the protein could potentially be valuable as an HIV-fighting tool for both infants and adults that are either HIV-positive or at risk of contracting the infection.The research, published in Proceedings of the National Academy of Sciences, was inspired by previous work done by other researchers showing that, both in tissue cultures(组织培养) and live mice, breast milk from HIV-negative mothers was naturally endowed with HIV-fighting properties. Scientists suggested that a few different proteins in the milk could potentially be responsible, but no one knew which one.As part of the study, the researchers divided breast milk into smaller fractions(部分) made up of specific proteins via a number of filters(过滤器) — separating the proteins by size, electrical charge and other characteristics — and tested which of these fractions, when added to a tissue culture, prevented the cells from being infected by HIV. Eventually, they found that one particular protein was present in all the HIV-resistant fractions but in none of the others: Tenascin CTenascin C works by blocking a key protein on HIV’s envelope that normally ties up to a receptor on a T cell’s membrane called CCR5. In doing so, Tenascin C prevents HIV from mixing with the T cell and injecting its RNA inside.Still, the researchers say that other natural elements in milk might play a role in fighting HIV as well. "It’s clearly not the whole story, because we do have samples that have low amounts of this protein but still have HIV-neutralizing activity," the study’s lead author Permar says. "So it may be acting in concert with other antiviral and antimicrobial factors in the milk."Whatever those other factors are, though, the finding vindicates (证明) recent changes to UN guidelines that recommend even HIV-positive mothers in resource-poor countries should breastfeed, if they’re taking anti-retroviral drugs to combat their own infection.The next steps, Permar says, are determining which area of Tenascin C is active and whether it can effectively prevent transmission in a live animal. If it works, it could potentially be incorporated(并入) into an HIV drug with broader applications. It’s even possible that it could someday be adapted to reduce the risk of HIV transmission in adults as well as infants.1.What can we know about Permar and the research group according to the passage?A.They have found a cure for HIVB.They have helped change UN guidelinesC.They will do more researches on Tenascin CD.Their finding is based on their previous work2.What is the main idea of Paragraph 1?A.The breast milk from an infected mother doesn’t contain HIV at allB.Only a small percentage of infants breastfed by infected mothers catches HIVC.The possibilities of infants catching HIV have nothing to do with infected mothersD.Children feeding on infected mothers’ milk won’t catch HIV though exposed to it often3.Why did the researchers divide breast milk into smaller fractions?A.To find out Tenascin CB.To make up specific proteinsC.To add them to a tissue cultureD.To test what prevents cells from being infected4.Which of the following about Tenascin C is true?A.It has become an effective tool in fighting HIVB.It is the key protein on HIV’s envelopeC.It can prevent transmission in a live animal effectivelyD.It helps prevent mother-to-child transmission of HIV

I've made new friends and am ____ at college. I think I'm enjoying being a college student.A. doing businessB. doing wrongC. doing harmD. doing well

In which of the following places have snakes never been foundA. In green forests.B. In the Pacific Ocean.C. In dry deserts.D. In the North Pole region.

In April 2015, about three years after moving his team into an open concept office, Charlie moved the company into a 10,000-square-foot office where everyone now has their own space—complete with closing doors.Numerous companies have embraced the open office—about 70% of U.S. offices are open concept—and by most accounts, very few have moved back into traditional spaces with offices and doors. But research findings that we’re 15% less productive, we have immense trouble concentrating and we’re twice as likely to get sick in open working spaces, have contributed to a growingreaction against open offices.There’s one big reason we’d all love a space with four walls and a door that shuts: focus. The truth is,we can’t multitask and small distractions can cause us to lose focus for upwards of 20 minutes. What’s more, certain open spaces can negatively impact our memory. It’s not so obvious to us each day, but we offload memories—often little details—into our surroundings, says Sally Augustin, an environmental psychologist in La Grange Park, Illinois.Of course, it’s important for us to bond and to get to know each other. But there are plenty of ways to bond in closed offices. Charlie’s team, for instance, eats lunch together every day. A few ideas come out of lunch time chats, he says, but most are developed from more focused brainstorming sessions.1.What did Charlie do in April 2015?A) He started a new branch office.B) He called for building an open office.C) He moved his team into closed offices.D) He moved his company into another city.2.What bad influence do open offices have according to the research?A) People will have less privacy.B) People get tired easily.C) People are 50% less productive.D) People have problems in focusing.3.What does the environmental psychologist Sally Augustin think of working in open spaces?A) It causes the focus loss for 20 minutes.B) It impacts negatively on our memory.C) It distracts us into details in the workplace.D) It leads to the failure of multitasks.4.What do we know about closed office environment according to the passage?A) People don’t have chances to bond if they work in closed offices.B) Working in closed offices is twice as likely for people to get sick.C) Most ideas come out of brainstorming sessions for those in closed offices.D) People are less effective when they are in a closed office environment.

Instead of going to school, this disabled man taught himself ____ to college level.A. step by stepB. in timeC. for a whileD. all the way

Questions 5 to 7 are based on the news report you have just heard.-|||-5.A) Raise postage rates. B) Improve its services.-|||-C)Close some of its post offices. D)Redesign delivery routes.-|||-6.A)Closing offices on holidays. B)Shortening business hours.-|||-C) Computerizing mail sorting processes. D)Stopping mail delivery on Saturdays.-|||-7.A)A lot of controversy will arise. B)Taxpayers will be very pleased.-|||-C)Many people will begin to complain. D)Many post office staff will lose their jobs

6 Complete the sentences by translating-|||-the Chinese into English,using the inversion-|||-structure beginning with so or nor.-|||-Model 1: Tokens of her childhood will await her.-|||-__ (我们也一样),with-|||-open arms.-|||-→Tokens of her childhood will await her.-|||-So will we with open arms.-|||-Model 2: He says politely, "I don`t care for any."-|||-__ (我也不想吃)-|||-→He says politely,"I don`t care for any."-|||-Nor would I.-|||-1 All of Justin`s pain disappeared. __-|||-__-|||-(他的腿也不痛了).-|||-2 His father doesn`t have great hopefo him now.-|||-__-|||-(他的母亲也一样).-|||-3 CNN then reported the stopy and __-|||-__ __ __-|||-(其他电视新闻节目和各大报纸也都报道了).

Entertainment is an activity designed to give pleasure or relaxation to a(n)_who may participate in it passively as in watching opera or a movie, or actively as in games.A. audienceB. onlookerC. bystanderD. viewer

All the students should develop morally, intellectually and physically.