单选题Certainly no creature in the sea is odder than the common sea cucumber(海参). All living creatures, especially human beings, have their peculiarities, but everything about the little sea cucumber seems unusual. What else can be said about an odd animal that, among other eccentricities, eats mud, feeds almost continuously day and night but can live without eating for long periods, and can be poisonous hut is considered supremely edible by gourmets(美食家) ? For some fifty million years, despite all its eccentricities, the sea cucumber has subsisted on its diet of mud. It is adaptable enough to live attached to rocks by its tube feet, under rocks in shallow water, or on the surface of mud fiats. Common in cool water on both Atlantic and Pacific shores, it has the ability to suck up .mud or sand and digest whatever nutrients are present. Sea cucumbers come in a variety of colors, ranging from black to reddish-brown to sandcolor and nearly white. One form even had vivid purple tentacles. Usually the creatures are cucumbers-shaped——hence their name——and because they are typically rock inhabitants, this shape, combined with flexibility, enables them to squeeze into narrow cracks where they are safe from predators and ocean currents. Although they have voracious appetites, eating day and night, sea cucumbers have the capacity to become inactive and live at a low metabolic rate feeding sparingly or not at all for long periods, so that the marine organisms that provide their food have a chance to multiply. If it were not for this faculty, they would devour all the food available in a short time and would probably starve themselves out' of existence. But the most spectacular thing about the sea cucumber is the way it defends itself. Its major enemies are fish and crabs, when attacked, it squirts all its internal organs into the water. It also casts off attached structures such as tentacles. The sea cucumber will eviscerate排除内脏) and regenerate itself if it is attacked or even touched; it will do the same if the surrounding water temperature is too high or if the water becomes too polluted.

单选题Stage Fright Fall down as you come onstage. That"s an odd trick. Not recommended. But it saved the pianist Vladimir Feltsman when he was a teenager back in Moscow. The veteran cellist (大提琴演奏家) Mstislav Rostropovieh tripped him purposely to cure him of pre-performance panic. Mr. Feltsman said, "All my fright was gone. I already fell. What else could happen?" Today, music schools are addressing the problem of anxiety in classes that deal with performance techniques and career preparation. There are a variety of strategies that musicians can learn to fight stage fright and its symptoms: icy fingers, shaky limbs, racing heart, blank mind. Teachers and psychologists offer wide-ranging advice, from basics like learning pieces inside out, to mental discipline, such as visualizing a performance and taking steps to relax. Don"t deny that you"re jittery (紧张不安的), they urge; some excitement is natural, even necessary for dynamic playing. And play in public often, simply for the experience. Psychotherapist Diane Nichols suggests some strategies for the moments before performance, "Take two deep abdominal breaths, open up your shoulders, then smile," she says. "And not one of these "please don"t kill me" smiles. Then choose three friendly faces in the audience, people you would communicate with and make music to, and make eye contact with them." She doesn"t want performers to think of the audience as a judge. Extreme demands by mentors or parents are often at the root of stage fright, says Dorothy Delay, a well-known violin teacher. She tells other teachers to demand only what their students are able to achieve. When Lynn Harrell was 20, he became the principal cellist of the Cleverland Orchestra, and he suffered extreme stage fright. "There were times when I got so nervous. I was sure the audience could see my chest responding to the throbbing. It was just total panic. I came to a point where I thought, "If I have to go through this to play music, I think I"m going to look for another job."" Recovery, he said, involved developing humility-recognizing that whatever his talent, he was fallible, and that an imperfect concert was not a disaster. It is not only young artists who suffer, of course. The legendary pianist Vladimir Horowitz"s nerves were famous. The great tenor Franco Corelli is another example. "They had to push him on stage," Soprano Renata Scotto recalled. Actually, success can make things worse. "In the beginning of your career, when you"re scared to death, nobody knows who you are, and they don"t have any expectations," Soprano June Anderson said. "There"s less to lose. Later on, when you"re known, people are coming to see you, and they have certain expectations. You have a lot to lose." Anderson added, "I never stop being nervous until I"ve sung my last note."

单选题As soon as we crossed the border, enemy troops started {{U}}firing{{/U}} at our troops.

单选题Mr. Bill has never been to China. {{U}}As a result{{/U}} he knows little about this country.

单选题Greene spent a brief time at Cambridge.A. hardB. goodC. shortD. long

单选题A dark suit ismore suitable for the evening party.A. favorableB. suitableC. preferableD. proper

单选题I remember lots of things. A．much B．large C．big D．many

单选题We need to extract the relevant financial data.A. storeB. saveC. obtainD. review

单选题He was a very smart boy but he made a foolish decision this time.A. cleverB. sillyC. braveD. shy

单选题I don"t quite follow what she is saying.

单选题We should not sacrifice environmental protections to foster economic growth. A．reduce B．promote C．realize D．give

单选题I wonder what your aim in life is.

单选题This reminds me of lots of things.A. muchB. someC. bigD. many

单选题London's First Light Rail System The Docklands Light Railway (DLR) took just three years to build at a cost of ￡77 million. It is London's first Light Rail System, but its route follows that of a number of older lines, which carried the nineteenth century railways through the crowded districts of the East End. The section of the line from the Tower Gateway Station to Poplar follows the line of one of London's earliest railways, the London on board each vehicle, Train Captains, who are also fully qualified drivers, are equipped with two-way radios to maintain contact with central control. There are passenger lifts, and self-service ticket machines, at every station.

单选题They strolled around the lake for an hour or so. A. ran B. rolled C. walked D. raced

单选题The maximum speed of this car is 150 miles per hour.A. highestB. lowestC. minimumD. supreme

单选题A Phone That Knows You"re Busy It"s a modern problem: you"re too busy to be disturbed by incessant (连续不断的) phone calls so you turn your cellphone off. But if you don"t remember to turn it back on when you"re less busy, you could miss some important calls. If only the phone knew when it was wise to interrupt you, you wouldn"t have to turn it off at all. Instead, it could let calls through when you are not too busy. A bunch of behavior sensors (传感器) and a clever piece of software could do just that, by analyzing your behavior to determine if it"s a good time to interrupt you. If built into a phone, the system may decide you"re too busy and ask the caller to leave a message or ring back later. James Fogarty and Scott Hudson at Camegie Mellon University in Pennsylvania based their system on tiny microphones, cameras and touch sensors that reveal body language and activity. First they had to study different behaviors to find out which ones strongly predict whether your mind is interrupted. The potential "busyness" signals they focused on included whether the office doors were left open or closed, the time of day, if other people were with the person in question, how close they were to each other, and whether or not the computer was in use. The sensors monitored these and many other factors while four subjects were at work. At random intervals, the subjects rated how interruptible they were on a scale ranging from "highly interruptible" to "highly not-interruptible". Their ratings were then correlated with the various behaviors. "It is a shotgun (随意的) approach: we used all the indicators we could think of and then let statistics find out which were important," says Hudson. The model showed that using the keyboard, and talking on a landline or to someone else in the office correlated most strongly with how interruptible the subjects judged themselves to be. Interestingly, the computer was actually better than people at predicting when someone was too busy to be interrupted. The computer got it right 82 per cent of the time, humans 77 per cent. Fogarty speculates that this might be because people doing the interrupting are inevitably biased towards delivering their message, whereas computers don"t care. The first application for Hudson and Fogarty"s system is likely to be in an instant messaging system, followed by office phones and cellphones. "There is no technological roadblock (障碍) to it being deployed in a couple of years," says Hudson.

单选题I was surprised to find that they all fell in with my suggestion at once.

单选题The trains on the DLR are controlled by

单选题Beef is an excellent material of iron.