When travelling overseas，do you buy water in plastic bottles or take your chances with tap water?Imagine you are wandering about on a Thai island or __26__ the ruins of Angkor.It's hot so you grab a bottle of water from a local vendor.It's the safe thing to do，right?The bottle is __27__ ，and the label says "pure water".But maybe what's inside is not so __28__ .Would you still be drinking it if you knew that more than 90 percent of all bottled water sold around the world __29__ microplastics?

That's the conclusion of a recently __30__ study，which analysed 259 bottles from 11 brands sold in nine countries，__31__ an average of 325 plastic particles per litre of water.These microplastics included a __32__ commonly known as PET and widely used in the manufacture of clothing and food and __33__ containers.The study was conducted at the State University of New York on behalf of Orb Media，a journalism organisation.About a million bottles are bought every minute，not only by thirsty tourists but also by many of the 2.1 billion worldwide who live with unsafe drinking water.

Confronted with this __34__ ，several bottled-water manufacturers including Nestle and Coca-Cola undertook their own studies using the same methodology.These studies showed that their water did contain microplastics，but far less than the Orb study suggested.Regardless，the World Health Organisation has launched a review into the __35__ health risks of drinking water from plastic bottles.

空白处27.应填

长城
说到中国文化，不能不提到长城。从公元前7世纪到公元16世纪，在大约2 200年的时间里，先后有19个朝代修建过长城，所修的长城长达10万千米以上。主要的长城修建工程是在秦代、汉代和明代完成的。现今存有遗迹的主要是明长城，从东边入海口的山海关(Shanhai Pass)开始，一直到沙漠深处的嘉峪关(Jiayu Pass)，全长约6700千米。长城是世界历史上最伟大的工程之一，其建造时间之长、参与人数之多、工程难度之大，在世界上无出其右。

as conj.（正当）……的时候；如同；由于
　　________至于，关于
　　________好比是，可谓，在某种程度上

Is College a Worthy Investment?

(A）Why are we spending so much money on college? And why are we so unhappy about it? We all seem to agree that a college education is wonderful, and yet strangely we worry when we see families investing so much in this supposedly essential good. Maybe it's time to ask a question that seems almost sacrilegious (大不敬的) : is all this investment in college education really worth it?

(B）The answer, I fear, is no. For an increasing number of lads, the extra time and money spent pursuing a college diploma will leave them worse off than they were before they set foot on campus.

(C）For my entire adult life, a good education has been the most important thing for middle-class households. My parents spent more educating my sister and me than they spent on their house, and they're not the only ones. ..and, of course, for an increasing number of families, most of the cost of their house is actually the cost of living in a good school district. Questioning the value of a college education seems a bit like questioning the value of happiness, or fun.

(D）The average price of all goods and services has risen about 50 percent. But the price of a college education has nearly doubled in that time. Is the education that today's students are getting twice as good? Are new workers twice as smart? Have they become somehow massively more expensive to educate?

(E）Perhaps a bit. Richard Vedder, an Ohio University economics professor, says, "I look at the data, and I see college costs rising faster than inflation up to the nud-1980s by l percent a year. Now I see them rising 3 to 4 percent a year over inflation. What has happened? The federal government has started dropping money out of airplanes. " Aid has increased, subsidized (补贴的) loans have become available, and "the universities have gotten the money. " Economist Bryan Caplan, who is writing a book about education, agrees: "It's a giant waste of resources that will continue as long as the subsidies continue. "

(F）Promotional literature for colleges and student loans often speaks of debt as an "investment in yourself. " But an investment is supposed to generate income to pay off the loans. More than half of all recent graduates are unemployed or in jobs that do not require a degree, and the amount of student-loan debt carried by households has increased more than five times since 1999. These graduates were told that a diploma was all they needed to succeed, but it won't even get them out of the spare bedroom at Mom and Dad's. For many, the most visible result of their four years is the loan payments, which now average hundreds of dollars a month on loan balances in the tens of thousands.

(G）It's true about the money-sort of. College graduates now make 80 percent more than people who have only a high-school diploma, and though there are no precise estimates, the wage premium (高出的部分) for an outstanding school seems to be even higher. But that's not true of every student. It's very easy to spend four years majoring in English literature and come out no more employable than you were before you went in. Conversely, chemical engineers straight out of school can easily make almost four times the wages of an entry-level high-school graduate.

(H）James Heckman, the Nobel Prize-winning economist, has examined how the returns on education break down for individuals with different backgrounds and levels of ability. " Even with these high prices, you're still finding a high return for individuals who are bright and motivated," he says. On the other hand, "if you're not college ready, then the answer is no, it's not worth it. " Experts tend to agree that for the average student, college is still worth it today, but they also agree that the rapid increase in price is eating up more and more of the potential return. For borderline students, tuition (学费) rise can push those returns into negative territory.

(I）Everyone seems to agree that the government, and parents, should be rethinking how we invest in higher education-and that employers need to rethink the increasing use of college degrees as crude screening tools for jobs that don't really require college skills. "Employers seeing a surplus of college graduates and looking to fill jobs are just adding that requirement," says Vedder. "In fact, a college degree becomes a job requirement for becoming a bar-tender. "

(J）We have started to see some change on the finance side. A law passed in 2007 allows many students to cap their loan payment at 10 percent of their income and forgives any balance after 25 years. But of course, that doesn't control the cost of education; it just shifts it to taxpayers. It also encourages graduates to choose lower-paying careers, which reduces the financial return to education still further. "You're subsidizing people to become priests and poets and so forth," says Heckman. "You may think that's a good thing, or you may not. " Either way it will be expensive for the government.

(K）What might be a lot cheaper is putting more kids to work. Caplan notes that work also builds valuable skills-probably more valuable for- kids who don't naturally love sitting in a classroom. Heckman agrees wholeheartedly: " People are different, and those abilities can be shaped. That's what we've learned, and public policy should recognize that. "

(L）Heckman would like to see more apprenticeship-style (学徒式) programs, where kids can learn in the workplace-learn not just specific job skills, but the kind of "soft skills," like getting to work on time and getting along with a team, that are crucial for career success. "It's about having mentors (指导者)and having workplace-based education, "he says." Time and again I've seen examples of this kind of program working.

(M）Ah, but how do we get there from here? With better public policy, hopefully, but also by making better individual decisions. "Historically markets have been able to handle these things," says Vedder," and I think eventually markets will handle this one. If it doesn't improve soon, people are going to wake up and ask, 'Why am I going to college?' "

Over fifty percent of recent college graduates remain unemployed or unable to find a suitable job.

Do In-Class Exams Make Students Study Harder?

Research suggests they may study more broadly for the unexpected rather than search for answers.

(A)I have always been a poor test-taker.So it may seem rather strange that I have returned to college to finish the degree I left undone some four decades ago.I am making my way through Columbia University，surrounded by students who quickly supply the verbal answer while I am still processing the question.

(B)Since there is no way for me to avoid exams，I am currently questioning what kind are the most taxing and ultimately beneficial.I have already sweated through numerous in-class midterms and finals，and now I have a professor who issues take-home ones.I was excited when I learned this，figuring I had a full week to do the research，read the texts，and write it all up.In fact，I was still rewriting my midterm the morning it was due.To say I had lost the thread is putting it mildly.

(C)As I was suffering through my week of anxiety，overthinking the material and guessing my grasp of it，I did some of my own polling among students and professors.David Eisenbach，who teaches a popular class on U.S.presidents at Columbia，prefers the in-class variety.He believes students ultimately learn more and encourages them to form study groups."That way they socialize over history outside the class，which wouldn't happen without the pressure of an in-class exam，" he explained."Furthermore，in-class exams force students to learn how to perform under pressure，an essential work skill."

(D)He also says there is less chance of cheating with the in-class variety.In 2012，125 students at Harvard were caught up in a scandal when it was discovered they had cheated on a take-home exam for a class entitled "Introduction To Congress." Some colleges have what they call an "6honor code，" though if you are smart enough to get into these schools，you are either smart enough to get around any codes or hopefully，too ethical to consider doing so.As I sat blocked and clueless for two solid days，I momentarily wondered if I couldn't just call an expert on the subject matter which I was tackling，or someone who took the class previously，to get me going.

(E)Following the Harvard scandal，Mary Miller，the former dean of students at Yale，made an impassioned appeal to her school's professors to refrain from take-home exams."Students risk health and well being，as well as performance in other end-of-term work，when faculty offers take-home exams without clear，time-limited boundaries，" she told me."Research now shows that regular quizzes，short essays，and other assignments over the course of a term better enhance learning and retention."

(F)Most college professors agree the kind of exam they choose largely depends on the subject.A quantitative-based one，for example，is unlikely to be sent home，where one could ask their older brothers and sisters to help.Vocational-type classes，such as computer science or journalism，on the other hand，are often more research-oriented and lend themselves to take-home testing.Chris Koch，who teaches "History of Broadcast Journalism" at Montgomery Community College in Rockville，Maryland，points out that reporting is about investigation rather than the memorization of minute details."In my field，it's not what you know—it's what you know how to find out，" says Koch."There is way too much information，and more coming all the time，for anyone to remember.I want my students to search out the answers to questions by using all the resources available to them."

(G)Students' test-form preferences vary，too，often depending on the subject and course difficulty."I prefer take-home essays because it is then really about the writing，so you have time to edit and do more research，" says Elizabeth Dresser，a junior at Barnard.Then there is the stress factor.Francesca Haass，a senior at Middlebury，says，"I find the in-class ones are more stressful in the short term，but there is immediate relief as you swallow information like mad，and then you get to forget it all.Take-homes require thoughtful engagement which can lead to longer term stress as there is never a moment when the time is up." Meanwhile，Olivia Rubin，a sophomore at Emory，says she hardly even considers take-homes true exams."If you understand the material and have the ability to articulate(说出)your thoughts，they should be a breeze."

(H)How students ultimately handle tests may depend on their personal test-taking abilities.There are people who always wait until the last minute，and make it much harder than it needs to be.And then there are those who，not knowing what questions are coming at them，and having no resources to refer to，can freeze.And then there are we rare folks who fit both those descriptions.

(I)Yes，my advanced age must factor into the equation(等式)， in part because of my inability to access the information as quickly.As another returning student at Columbia，Kate Marber，told me，"We are learning not only all this information，but essentially how to learn again.Our fellow students have just come out of high school.A lot has changed since we were last in school."

(J)If nothing else，the situation has given my college son and me something to share.When I asked his opinion on this matter，he responded，"I like in-class exams because the time is already reserved，as opposed to using my free time at home to work on a test，" he responded.It seems to me that a compromise would be receiving the exam questions a day or two in advance，and then doing the actual test in class with the ticking clock overhead.

(K)Better yet，how about what one Hunter College professor reportedly did recently for her final exam：She encouraged the class not to stress or even study，promising that，"It is going to be a piece of cake."When the students came in，sharpened pencils in hand，there was not a blue book in sight.Rather，they saw a large chocolate cake and they each were given a slice.

Different students may prefer different types of exams.

西安
西安，古代名为长安，位于中国西北部，隶属陕西省。西安曾经是中国多个朝代的都城，有很多名胜古迹，历史辉煌。每年都有成千上万的游客来到这里，他们大多是来参观位于西安郊区的兵马俑博物馆（Museum of Terra Cotta Warriors）的。游览西安的最佳时间是春秋两个季节，因为这两个季节的天气相对干燥宜人。西安在7月至9月的一段时间内会经常刮湿润的季风（monsoon），冬季又相当寒冷。

Just because they can't sing opera or ride a bicycle doesn't mean that animals don't have culture.There's no better example of this than killer whales.As one of the most __26__ predators （食肉动物），killer whales may not fit the __27__ of a cultured creature.However，these beasts of the sea do display a vast range of highly __28__ behaviors that appear to be driving their genetic development.

The word "culture"comes from the Latin "colere，"which __29__ means "to cultivate."In other words，it refers to anything that is __30__ or learnt，rather than instinctive or natural.Among human populations，culture not only affects the way we live，but also writes itself into our genes，affecting who we are.For instance，having spent many generations hunting the fat marine mammals of the Arctic，the Eskimos of Greenland have developed certain genetic __31__ that help them digest and utilize this fat- rich diet，thereby allowing them to __32__ in their cold climate.

Like humans，killer whales have colonized a range of different __33__ across the globe，occupying every ocean basin on the planet with an empire that __34__ from pole to pole.As such，different populations of killer whales have had to learn different hunting techniques in order to gain the upper hand over their local prey （猎物）.This，in turn，has a major effect on their diet，leading scientists to __35__ that the ability to learn population-specific hunting methods could be driving the animals，genetic development.

空白处35.应填