Biuret method can be used to detect the concentration of amino acids and proteins in solution.

A、street people who sleep in subways, bus stations, parks, cars, or the streets and have roamed the streets for months or even years

B、people who are utilizing shelters operated by local authorities or private charities

C、people who sleep in hotels

D、both A and B

A、Speciation may be defined as the different physico-chemical forms of an element which together comprise its total concentration in a given sample.

B、Because the total concentration of a polluting element in an environmental sample provides no information concerning the fate of the element in terms of its interaction with sediment, its ability to cross biological membranes, or its resultant toxicity of a metal. Changes in speciation may dramatically affect the toxicity of a metal. Thus, in order to assess the environmental impact of an element, we must have some information concerning its speciation.

C、Some analyses can only be made at, or very close to, the sampling site.Readily portable and robust analytical equipment or remote sensing devices are thus required.

D、The main shortcoming to the computational approach is the reliability of the data used. The results of the model are only as good as the parameters on which they depend and any shortcomings in either the analytical concentration of the system under investigation or in the thermodynamic data will result in a very misleading speciation profile.

What can be concluded from the last paragraph?

A．Legalization of the kidney sales is beneficial to both the sellers and buyers.

B．More regulations are necessary to improve the current sorry state of affairs.

C．Kidney sales are in the buyers" favor because sellers gain less but lose more.

D．We should not let instinct trump logic, especially in life-and-death situations.

When philanthropist Jeffrey Brewer heard the founder of Appro TEC speak in San Francisco recently, he was intrigued by the nonprofit's high-tech efforts to fight poverty and create jobs in Africa. But he wanted to learn more before shelling out money, so he scheduled a meeting with the founder. "I wasn't sure it was as good as it sounded," says Brewer, who lives in New York. Six months later, he boarded a plane for Kenya—at ApproTEC's behest—to check out their programs in person. "It turned out to be better."

Forget slide shows or annual reports. Charitable organizations are finding that field visits are far more effective marketing tools for deep-pocket donors looking for new experiences. The invitation—only travel programs allow donors, who typically don't mind paying their own way, to see firsthand what their money can accomplish. Such field trips—whether to AIDS orphanages in China, famine-relief programs in Sudan or earthquake-proof building sites in Indonesia—almost always result in increased awareness and bigger checks. Some donors become more active in the aid organization—Brewer now chairs ApproTEC's boardd—or throw fund-raising parties. "Lifetime passionate supporters means first they fall in love with the people and places that they meet," says Sherry Villanueva, Who started organizing trips two years ago as a board member of Direct Relief International, which supplies medical and financial aid to locally run health programs. "We're not sitting around on a fancy deck somewhere with waiters in white gloves."

Indeed, donor trips tend to mix fun with the fund-raising. Miracle Comers of the World, which provides small-business training and housing for young adults in Tanzania, will host its first donor trip in August, with a safari in addition to the ribbon—cutting ceremony at its new housing project. Last month, the London-based International Childcare Trust cycled 300 kilometers in southern India to raise money for children orphaned by the tsunami. The Philanthropy Workshop, a program cosponsored by the Rockefeller Foundation that acts as a boot camp for new donors, recently sent 14 participants to Uganda for a week to look at innovative school reform. for girls and sustainable farming—as well as some gorillas in the bush.

While some critics argue that charities should focus on honing their mission statements instead of organizing adventure trips, others say only a field visit can change a donor's view of the world. "I had a lot of ideas of how to fix Africa before I went over—and all of them were wrong," says Brewer. "I felt very humbled." Roderic Mast, the founder of Conservation International's donor travel program, CI-Sojourns, which enables top supporters to investigate endangered ecosystems around the globe, says he owes the rise in million-dollar-plus contributions to the growing popularity of his nature trips, up from three in 2000 to 13 this year. On one recent trip, Mast recalls how he left a donor and his wife on a beach in Michoacan, Mexico, at night to watch a nesting sea turtle. At breakfast the next morning, they marveled over how the mother gently covered her eggs and then spread sand over a wide area to obscure their location. "The experience was so moving, he cried," says Mast, a marine biologist, of the donor. "No amount of direct mail is ever going to achieve that."

What does the author want to tell us from the example of Jeffrey Brewer, the philanthropist?

I. Read the following statements and choose the correct answer. There is no denying that students should learn something about how computers work, just as we expect them at least to understand that the internal-combustion engine (内燃机) has something to do with burning fuel, expanding gases and pistons (活塞) being driven. For people should have some basic idea of how the things that they use do what they do. Further, students might be helped by a course that considers the computer’s impact on society. But that is not what is meant by computer literacy. For computer literacy is not a form of literacy (读写能力); it is a trade skill that should not be taught as a liberal art. Learning how to use a computer and learning how to program one are two distinct activities. A case might be made that the competent citizens of tomorrow should free themselves from their fear of computers. But this is quite different from saying that all ought to know how to program one. Leave that to people who have chosen programming as a career. While programming can be lots of fun, and while our society needs some people who are experts at it, the same is true of auto repaid and violin-making. Learning how to use a computer is not that difficult, and it gets easier all the time as programs become more “user-friendly”. Let us assume that in the future everyone is going to have to know how to use a computer to be a competent citizen. What does the phrase “learning to use a computer” mean? It sounds like “learning to drive a car”, that is, it sounds as if there is some set of definite skills that, once acquired, enable one to use a computer. In fact, “learning to use a computer” is much more like “learning to play a game”, but learning the rules of one game may not help you play a second game, whose rules may not be the same. There is no such a thing as teaching someone how to use a computer. One can only teach people to use this or that program and generally that is easily accomplished. 3. Learning to use a computer is getting easier all the time because ________.

A、A) programs are becoming less complicated

B、B) programs are designed to be convenient to users

C、C) programming is becoming easier and easier

D、D) programs are becoming readily available to computer users

1. Mnemonics are tools which can help you to improve your memory. 2. The fundamental principle of mnemonics is to make full use of the best functions of the brain to store information. 3. Information we have to remember is almost always presented in different ways. (Unfortunately information we have to remember is almost always presented in only one way — as words printed on a page.) 4. We can do four things to form striking images, which will help to make our mnemonics more effective. 5. There is one basic principle in the use of mnemonics. (There are three fundamental principles underlying the use of mnemonics.) 6. Association is what we use to create and strengthen imagination. (Imagination is what you use to create and strengthen the associations needed to create effective mnemonics.) 7. You can choose any imagery to use in your mnemonics as long as it is helpful. 8. You can create associations by linking things using the same stimuli.

In the following sentence, the phrase "in the car" could be used(i)to show where the biting took place or(ii)to specify that it was the man in the car that was bitten. How would the tree diagrams for(i)and(ii)differ? The dog bit the man in the car.

【填空题】Lesson 4 课后作业-词汇填空 marking Rejected takeoff Runway incursion consequence sign expeditiously airstrip stopway 1. The________is an area beyond the runway which can be used for deceleration in the event of a rejected takeoff. 2. A_________is an incident where an unauthorized aircraft, vehicle or person is on a runway, which adversely affects runway safety, as it creates the risk that an airplane taking off or landing will collide with the object. 3. In order to avoid the conflicting traffic, Airbus 320 was instructed by the ATC to climb _______to and maintain 7000 meters. 4. There can be many reasons for deciding to perform a _________, but they are usually due to suspected or actual technical failures, like an engine failure such as a compressor stall occurring during the takeoff run. 5. An_________ is a small aerodrome that consists only of a runway with perhaps fueling equipment. 6. The light array is located at the intersection of two runways and a taxiway. This _________indicates where an aircraft is to hold before entering a runway. 7. Layouts with parallel runways and/or intersecting runways increase the probability of both ATC issuing conflicting clearances and, occurrence of incursions as a__________ of flight crew errors. 8. Airport guidance_________provide direction and information to taxiing aircraft and airport vehicles.