托福习题练习
| 托福考试易错题（2019/10/15） |
| 第1题：According to the professor, what is the relation between the mass and the lifetime of a star [Clink on 2 answers.] A、The more massive, the longer-liveD、 B、The more massive, the shorter-liveD、 C、The less massive, the longer-liveD、 D、The less massive, the shorter-liveD、 |
| 【多选题】： |
| 第2题：Geographers say that what defines a place are four properties: soil, climate, altitude, and aspect, or attitude to the Sun. Florida’’s ancient scrub demonstrates this principle. Its soil is pure silica, so barren it supports only lichens as ground cover.(It does, however, sustain a sand-swimming lizard that cannot live where there is moisture or plant matter (5) the soil.) Its climate, despite more than 50 inches of annual rainfall, is blistering desert plant life it can sustain is only the xerophytic, the quintessentially dry. Its altitude is a mere couple of hundred feet, but it is high ground on a peninsula elsewhere close to sea level, and its drainage is so critical that a difference of inches in elevation can bring major changes in its plant communities. Its aspect is flat, direct, brutal―and subtropical. (10) Florida’’s surrounding lushness cannot impinge on its ’’desert scrubbiness. This does not sound like an attractive place. It does not look much like one either; Shrubby little oaks, clumps of scraggly bushes, prickly pear, thorns, and tangles. "It appear Said one early naturalist," to desire to display the result of the misery through which it has Passed and is passing."By our narrow standards, scrub is not beautiful; neither does it meet (15)our selfish utilitarian needs.Even the name is an epithet, a synonym for the stunted, the scruffy, the insignificant, what is beautiful about such a place The most important remaining patches of scrub lie along the Lake Wales Ridge, a chain of paleoislands running for a hundred miles down the center of Florida, in most places less than ten miles wide. R is relict seashore, tossed up millions of years ago when ocean levels (20) were higher and the rest of the peninsula was submergeD、That ancient emergence is precisely what makes Lake Wales Ridge so precious: it has remained unsubmerged , its ecosystems essentially undisturbed, since the Miocene er A、As a result, it has gathered to itself one of the largest collections of rare organisms in the worlD、Only about 75 plant species survive there, but at least 30 Of these are found nowhere else onEarth.The passage probably continues with a discussion of A、ancient scrub found in other areas of the country B．geographers who study Florida’’s scrub C．the climate of the Lake Wales Ridge D．the unique plants found on the Lake Wales Ridge |
| 【单选题】： |
| 第3题：The largest of the giant gas planets, Jupiter, with a volume 1,300 times greater thanEarth’s, contains more than twice the mass of all the other planets combineD、It is thought to be a gaseous and fluid planet without solid surfaces, Had it been somewhat more massive, Jupiter might have attained internal temperatures as high as the ignition point for nuclear reactions, and it would have flamed as a star in its own right. Jupiter and the other giant planets are of a low-density type quite distinct from the terrestrial planets: they are composed predominantly of such substances as hydrogen, helium, ammonia, and methane, unlike terrestrial planets. Much of Jupiter’s interior might be in the form of liquid, metallic hydrogen, Normally, hydrogen is a gas, but under pressures of millions of kilograms per square centimeter, which exist in the deep interior of Jupiter, the hydrogen atoms might lock together to form a liquid with the properties of a metal. Some scientists believe that the innermost core of Jupiter might be rocky, or metallic like the core ofEarth. Jupiter rotates very fast, once every 9.8 hours.As a result, its clouds, which are composed largely of frozen and liquid ammonia, have been whipped into alternating dark and bright bands that circle the planet at different speeds in different latitudes. Jupiter’s puzzling Great Red Spot changes size as it hovers in the Southern Hemisphere. Scientists speculate it might be a gigantic hurricane, which because of its large size (theEarth could easily fit inside it), lasts for hundreds of years. Jupiter gives off twice as much heat as it receives from the Sun. Perhaps this is primeval heat or beat generated by the continued gravitational contraction of the planet.Another starlike characteristic of Jupiter is its sixteen natural satellites, which, like a miniature model of the Solar System, decrease in density with distance—from rocky moons close to Jupiter to icy moons farther away. If Jupiter were about 70 times more massive, it would have become a star, Jupiter is the best-preserved sample of the early solar nebula, and with its satellites, might contain the most important clues about the origin of the Solar System. The author uses the word "puzzling" in line 15 to suggest that the Great Red Spot is A、the only spot of its kind B、not well understood C、among the largest of such spots D、a problem for the planet’s continued existence |
| 【单选题】： |
| 第4题： Artificial Intelligence Any discussion of artificial intelligence, orA、I., must inevitably start with the question of what exactly intelligence is. Unfortunately, it is not an easy matter to decide. Intelligence is normally defined as the ability to recognize relationships and to build upon them. However, computers can often do that better than humans, yet they are not therefore considered more intelligent.Desires, goals, and preferences are also important, as is a sense of self- awareness, when we talk about what we mean by artificial intelligence. The scope and depth of a program’s coverage of all of these attributes determine which of the two main sorts of artificial intelligence it belongs to. WeakA、I. is the main type of artificial intelligence that exists today. WeakA、I. programs do not attempt to mimic human consciousness or encapsulate the full range of human mental activity. Instead, they attempt to perform one particular problem-solving task very well. The most obvious example of such a program is the chess-playing computerDeepBlue, which, in May of 1997, became the first computer to defeat a current world champion in a standard tournament match.DeepBlue is clearly more intelligent than humans when it comes to chess, but it just as clearly has no greater consciousness that would allow it to compete with us in any other areA、Other examples of weakA、I. include computerized grammar checkers, e-mail spam filters, and Internet chat bots.Because these sorts of programs are limited to specific tasks, and because they have become so familiar to us, they are not often considered artificial intelligence programs by most members of the general publi C、Nevertheless, they all represent considerable advances in theA、I. field, and form the best examples of the progress computer scientists have made towards creating thinking machines. StrongA、I. is the other type of artificial intelligence and is what most people think of when they hear the term. StrongA、I. refers to computers that have a wide range of general cognitive abilities, including consciousness or self-awareness. No strongA、I. programs actually exist today, but scientists continue to work on developing one that works.At present, there are two main approaches to the creation of strongA、I. The first involves attempting to build a computer that is modeled after the human brain. The main problem with this approach is that scientists do not yet have a complete understanding of the human brain, so that any models based on it must necessarily be flaweD、In addition, the human brain is so complex that it is virtually impossible to create a computer model based on it with today’s processing technology. The second approach involves trying to create a strongA、I. program based on building up existing computer programs. This approach has the advantage of allowing scientists to make progress on strongA、I. software without having to first develop much mere powerful hardware, but also raises the interesting question of Whether or not they would even recognize success: a strongA、I. program that was not modeled after the human brain might not manifest its intelligence: ina manner noticeable to its programmers. Scientists and philosophers have long debated exactly how a computer might prove to us that it had developed genuine intelligence, yet no solid consensus exists. Indeed, we often find it difficult to judge another human being’s level of intelligence, so it is perhaps unsurprising that we find measuring a computer’s simulation of that ability nearly impossible. ■ A、One method for gaging the success of a strongA、I. program is called the Turing Test. ■ B、First proposed in the 1950s, a Turing Test works by having a judge or series of judges engage in a written conversation with hidden test subjects, some of whom are human and some of whom are actually computers. ■ C、The theory is that a compu |
| 【单选题】： |
| 第5题： {{B}}Narrator{{/B}} Listen to a part of a talk in a history lecture. |
A．To encourage students to thing about a similar personal experience.B．To elicit an answer from the students.
C．To create a feeling of relief from his students.
D．To engage his students.