2021年北师大大学考博英语真题试卷

2021年北师大大学考博英语真题试卷

2021年北京师范大学考博英语真题试卷 (总分68, 做题时间90分钟)

1. Reading Comprehension

The human ear contains the organ for hearing and the organ for balance. Both organs involve fluid-filled channels containing hair cells that produce electrochemical impulses when the hairs are stimulated by moving fluid. The ear can be divided into three regions: outer, middle, and inner. The outer ear collects sound waves and directs them to the eardrum separating the outer ear from the middle ear. The middle ear conducts sound vibrations through three small bones to the inner ear. The inner ear is a network of channels

containing fluid that moves in response to sound or movement. To perform the function of hearing, the ear converts the energy of pressure waves moving through the air into nerve impulses that me brain perceives as sound.

Vibrating objects, such as the vocal cords of a speaking person, create waves in me surrounding air. These waves cause the eardrum to vibrate with the same frequency. The three bones of the middle ear amplify and transmit the

vibrations to the oval window, a membrane on the surface of the cochlea, the organ of hearing. Vibrations of me oval window produce pressure waves in the fluid inside me cochlea. Hair cells in the cochlea convert the energy of the vibrating fluid into impulses that travel along the auditory nerve to the brain. The organ for balance is also located in the inner ear. Sensations related to body position are generated much like sensations of sound. Hair cells in the inner ear respond to changes in head position with respect to gravity and movement. Gravity is always pulling down on the hairs, sending a constant series of impulses to the brain. When the position of the head

changes―as when the head bends forward―the force on the hair cells changes its output of nerve impulses. The brain then interprets these changes to determine the head's new position. 1.

What can be inferred about the organs for hearing and balance? A Both organs evolved in humans at the same time. B Both organs send nerve impulses to the brain. C Both organs contain the same amount of fluid.

D Both organs are located in me ear's middle region. 2.

Hearing involves all of the following EXCEPT______. A motion of the vocal cords so that they vibrate B stimulation of hair cells in fluid-filled channels C amplification of sound vibrations

D conversion of wave energy into nerve impulses 3.

It can be inferred from Paragraphs 2 and 3 that the cochlea is a part of______.

A the outer ear B me eardrum C the middle ear D the inner ear 4.

What can be inferred from Paragraph 4 about gravity? A Gravity has an essential role in the sense of balance. B The ear converts gravity into sound waves in the air. C Gravity is a force that originates in the human ear. D The organ for hearing is not subject to gravity. 5.

In this passage, the author mainly explains______. A the organs of the human ear B the function of the hearing C the three regions of the ear D how the ear organ performs the hearing and balance

The geology of the Earth's surface is dominated by the particular

properties of water. Present on Earth in solid, liquid, and gaseous states, water is exceptionally reactive. It dissolves, transports, and precipitates many chemical compounds and is constantly modifying the face of the Earth. Evaporated from the oceans, water vapor forms clouds, some of which are

transported by wind over the continents. Condensation from the clouds provides the essential agent of continental erosion: rain. Precipitated onto the ground, the water trickles down to form brooks, streams, and rivers, constituting what is called the hydrographic network. This immense polarized network channels the water toward a single receptacle: an ocean. Gravity dominates this entire step in the cycle because water tends to minimize its potential energy by running from high altitudes toward the reference point that is sea level. The rate at which a molecule of water passes through the cycle is not random but is a measure of the relative size of the various reservoirs. If we define residence time as the average time for a water molecule to pass through one of the three reservoirs―atmosphere, continent, and ocean―we see that the times are very different. A water molecule stays, on an average, eleven days in the atmosphere, one hundred years on a continent and forty thousand years in the

ocean. This last figure shows the importance of the ocean as the principal reservoir of the hydrosphere but also the rapidity

of water transport on the continents. A vast chemical separation process takes places during the flow of water over the continents. Soluble ions such as calcium, sodium, potassium, and some magnesium are dissolved and transported. Insoluble ions such as aluminum, iron, and silicon stay where they are and form the thin, fertile skin of soil on which vegetation can grow. Sometimes soils are destroyed and transported mechanically during flooding. The erosion of the continents thus results from two closely linked and interdependent processes, chemical erosion and

mechanical erosion. Their respective interactions and efficiency depend on different factors. 6.

According to the passage, clouds are primarily formed by water______. A precipitating onto the ground

B changing from a solid to a liquid state C evaporating from the oceans D being carried by wind 7.

The passage suggests that the purpose of the \\to______.

A determine the size of molecules of water B prevent soil erosion caused by flooding

C move water from the Earth's surface to the oceans

D regulate the rate of water flow from streams and rivers 8.

What determines the rate at which a molecule of water moves through the cycle, as discussed in the third paragraph? A The potential energy contained in water.

B The effects of atmospheric pressure on chemical compounds. C The amounts of rainfall that fall on the continents. D The relative size of the water storage areas. 9.

All of the following are examples of soluble ions EXCEPT______. A magnesium B iron

C potassium D calcium 10.

The word \\A relationship B growth C influence D effectiveness

Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that come too close. The black hotels gravity pulls harder on the nearest part of the star, an

imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. Scientists say this uneven pulling is not the only

hazard facing the star. The strain of these unbalanced forces can also trigger a nuclear explosion powerful enough to destroy the star from within. Matthieu Brassart and Jean-Pierre Luminet of the Observatoire de Paris in Meudon, France, carried out computer simulations of the final moments of such an unfortunate star's life, as it veered towards a supermassive black hole. When the star gets close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would be complicated by shock waves generated during the flattening process and that no nuclear explosion should occur. The new simulations investigated the effects of shock waves in detail, and found that even when their effects are included, the conditions favor a nuclear explosion. \\― it will be completely

destroyed,\\it saves some of the star's matter from being devoured by the black hole. The explosion is powerful enough to hurl much of the star's matter out of the black hole's reach, he says. The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought mat several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so,

releasing ultraviolet light and X-rays. If stars disrupted near black holes really do explode, then they could in principle allow these events to be

detected at a much earlier stage, says Jules Hatpern of Columbia University in New York, US2. \\may make it possible to see the disruption of that star

immediately if it gets hot enough,\\Brassart agrees. \\it can be observed in the X-rays and gamma rays, but it's something that needs to be more

studied,\\researcher Chris Fryer of the Los Alamos National Laboratory in Los Alamos, New Mexico, US3, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case that they explode in the process. 11.

Something destructive could happen to a star that gets too close to a black hole. Which of the following destructive statements is NOT mentioned in the passage?

A The black hole could tear apart the star.

B The black hole could trigger a nuclear explosion in the star. C The black hole could dwindle its size considerably. D The black hole could devour the star. 12.

According to the third paragraph, researchers differed from each other in the problem of ______.

A whether nuclear reaction would occur

B whether the stars would increase its density and temperature C whether shock waves would occur

D whether the uneven forces would flatten the stars 13.

According to the fourth paragraph, which of the following is NOT true? A No nuclear explosion would be triggered inside the star. B The star would be destroyed completely.

C Much of the star's matter thrown by the explosion would be beyond the black hole's reach.

D The black hole would completely devour the star. 14.

What will happen several months after the explosion of the star? A The star's matter will move further away from by the black hole. B The black hole's matter will heat up.

C The torn star's matter will swirl into the black hole.

D The black hole's matter will release ultraviolet light and X-rays. 15. According to the context, the word \\means______. A confusion B tearing apart C interruption D flattening Our culture has caused most Americans to assume not only that our language is universal but that the gestures we use are understood by everyone. We do not realize that waving good-bye is the way to summon a person from the Philippines to one's side, or that in Italy and some Latin-American countries, curling the finger to oneself is a sign of farewell. Those private citizens who sent packages to our troops occupying

Germany after World War II and marked them GIFT to escape duty payments did not bother to find out that \\Gift\\means poison in German. Moreover, we like to think of ourselves as friendly, yet we prefer to be at least 3 feet or an arm's length away from others. Latins and Middle Easterners like to come closer and touch, which makes Americans uncomfortable. Our linguistic and cultural blindness and the casualness with which we take notice of the developed tastes, gestures, customs and languages of other countries, are

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