单选题______ do it ourselves, will you?

单选题The volume of the sun is about 1300000 ______ that of the earth. A) time B) times C) time in D) time of

单选题It is impossible to ______ this battle, for it raged for six months.

单选题— Who is that gentleman who talked to you just now? — He is my uncle ______ marriage.A. atB. toC. byD. with

单选题Scraps of food could soon be helping power your home, thanks to an ultra-cheap bacteria-driven battery. Its developers hope that instead of feeding the dog or making garden compost(混合肥料) ,organic household waste could top up your home's electricity. Although such "microbial fuel cells" (MFCs)have been developed in the past, they have always proved extremely inefficient and expensive. Now Chris Melhuish and technologists at the University of the West of England(UWE)in Bristol have come up with a simplified MFC that costs as little as ￡10 to make. Right now, their fuel cell runs only on sugar cubes, since these produce almost no waste when broken down, but they aim to move on to carrot power. "It has to be able to use raw materials, rather than giving it a refined fuel," says Melhuish. Inside the Walkman-sized battery, a colony of E. coil bacteria produce enzymes that break down carbohydrates, releasing hydrogen atoms. The cell also contains chemicals that drive a series of redox, or reduction and oxidation reactions, stripping electrons from the hydrogen atoms and delivering them steadily to the fuel cell's anode(正极). This creates a voltage that can be used to power a circuit. To prove the MFC works, the researchers are using it to power a small light-sensitive robot. And when a number of the cells are connected in series, they could power domestic appliances, running a 40-watt bulb for eight hours on about 50 grams of sugar. Earlier MFCs were inefficient because they relied on energy-hungry filters and pumps. By experimenting with different anode materials, the UWE team have figured out how to make their system work: they dump the bacteria and redox chemicals directly into the cell. In its current form, the UWE team says its organic battery can produce eight times as much power as any previous MFC. But Melhuish wants to improve this, both by scaling it up and finding a better mix of redox chemicals.

单选题[此试题无题干]

单选题Since the energy crisis, these big cars have become a real liability. They cost too much to run. A. lack of reliability B. substitute C. costly means of transport D. disadvantage

单选题The engine of the ship was out of order and the bad weather ______ the helpless of the crew at sea.A. added toB. resulted fromC. turned outD. made up

单选题Usually you will not get a shock by touching the electric ray in one place only because ______. A. a torpedo's electric cells contain more than one electric plates B. to complete the circuit, you have to touch the fish in two places C. the current in one place is not strong enough to give a shock D. the fish's electric cells are filled with jelly-like substance

单选题Customer: Excuse me, we ordered a coke without ice instead of this iced coke. Waiter: I"m sorry. ______

单选题Which of the following statements about news stories is TURE?

单选题It was not until she had arrived home ______ remembered her appointment with the doctor. A. when she B. that she C. and she D. so that she

单选题There are laws to specify the person (s) who will obtain a dead person"s ______ if no will exists.

单选题She will have to look for somewhere else to work, for she can't______such loud noise any longer.

单选题In the past, we needed ______ than today.

单选题As soon as the exams were over, the students all went their ______ ways.

单选题David is the______ holder of the 5,000-meter race world record, but there is no guarantee that he will win in the Olympic Games.

单选题It is very important that enough money ______ to fund the project. A. be collected B. must be collected C. is collected D. can be collected

单选题{{B}}Passage Four{{/B}} Diego Chiapello, legally blind since birth, isn't one of Italy's famous "mama's boys" who live with their parents into adulthood. The 27-year-old lives alone in Milan, works as a network administrator, loves diving and dreams of sailing across the Atlantic with a sight-impaired (有视力障碍的) crew. Obviously, he's not your average disabled person--but especially so in Italy. The country has more barriers to integration than almost anywhere else on the continent. Among European countries, Italy ranks third from the bottom in accessibility for the disabled, ahead of only Greece and Portugal. People who use wheelchairs, especially, find it difficult to navigate the country's cobblestone (鹅卵石) streets, ride buses or visit restaurants, shops and museums. Less than a quarter of Italy's disabled hold jobs compared with 47 percent for Europe. But the biggest obstacle for the country's physically challenged may, in fact, be the fabled Italian family. Because of the social defect that still attaches to disabilities, "they tend to keep disabled people at home and out of public view," explains Giovanni Marri, head of an employment training center in Milan that caters to the handicapped. Thus while 15 percent of the country's families include a disabled person, according to surveys, only 2 percent of Italians report going to school with a disabled person and only 4 percent work with one. Italians are beginning to recognize the problem. Over the past decade, the government has passed laws targeting everything from workplace discrimination to accessibility requirements. A recent study by the European Union found that 85 percent of Italians admit that public transportation and infrastructure (基础设施) are inadequate for the handicapped, and 97 percent say action is needed. But the biggest barrier is psychological. "Italian companies are afraid of hiring disabled people," says Chiapello. The only way to alter that, he says, is for Italy's disabled to do 'what he did--get out of the house and demand change.