2016西南交通大学考博英语真题

责编：王娟 2026-08-25

2016年西南交通大学考博英语真题

Ⅰ. Reading comprehension (40%; I mark each)

Passage 1

Our multimillion nerve-cell central nervous system has its roots in the scattered nerve cells of tiny, lowly organisms that lived in water half a billion years ago. Nerve cells evidently first appeared in coelenterates — “hollow-gutted” organisms like the hydra and the sea anemone. A coelenterate’s nerve network lacks any kind of centralized control. This probably began with flatworms -- the first creature to possess a head.

Specialized sense cells help flatworms respond more flexibly than sea anemones to outside stimuli. But like most animals without a backbone, flatworms act almost by instinct and reflex.

Intelligent behavior remained impossible until the appearance of relatively big, complex types of brain — the types we find among the backboned animas or vertebrates. The tiniest fish has a larger brain than the largest insect. But the development of a fish's three-part brain reflects that beast’s unintellectual priorities. Much of the forebrain deals only with smell. The midbrain handles vision and the hindbrain balance.

With early mammals the brain grew larger and more complex. Sense coordination shifted from the midbrain to the forebrain, a developing structure capped by folded cerebrum to handle memory and learning. Meanwhile the hindbrain gained a large cerebellum to coordinate complicated movements.

Advanced mammals such as monkeys, apes and human (the primates) have brains derived from ancestors that took to living in the trees, where vision mattered more than smell. Accordingly the once big “smell’’ part of the forebrain grew smaller, while the part that handles vision grew much larger.

1. With what topic is the passage mainly concerned?

A. The sensory organs of invertebrates.

B. The anatomy of tiny organisms

C. The origin of the brain and central nervous system.

D. The importance of vision for fish and advanced animals.

2. The hydra is a kind of .

A. flatworm B. coelenterate C. sea anemone D. nerve cell

3. In the last paragraph, the phrase “took to” could best be replaced by which of the following?

A. began B. fled to C. carried to D. became friendly toward

4. It can be inferred from the passage that insects do not have .

A. brains B. backbones C. nerve cells D. reflexes

5. According to the passage, what helps to coordinate the complex physical activity of a mammal?

A. The cerebellum B. The forebrain

C. The cerebrum D. The midbrain

Passage 2

Standing on the rim of the Grand Canyon, gazing across this giant wound in the Earth’s surface, a visitor might assume that the canyon had been caused by some ancient convulsion. In fact the events that produced the canyon, far from being sudden and cataclysmic, simply add up to the slow and orderly process of erosion.

Many millions of years ago the Colorado Plateau in the Grand Canyon area contained 10,000 more feet of rock than it does today and was relatively level. The additional material consisted of some 14-layered formations of rock. In the Grand Canyon region these layers were largely worn away over the course of millions of years.

Approximately 65 million years ago the plateau’s flat surface in the Grand Canyon area bulged upward from internal pressure; geologists refer to this bulging action as upwarping; it was followed by a general elevation of the whole Colorado Plateau, a process that is still going on. As the plateau gradually rose, shallow rivers that meandered across it began to run more swiftly and cut more definite courses. One of these rivers, located east of the upwarp, was the ancestor of the Colorado. Another river system called the Hualapai, flowing west of the upwarp, extended itself eastward by cutting back into the upwarp; it eventually connected with the ancient Colorado and captured its waters. The new river then began to carve out the 277-miIe-long trench that eventually became the Grand Canyon. Geologists estimate that this initial cutting action began no earlier than 10 million years ago.

Since then, the canyon forming has been cumulative. To the corrosive force of the river itself have been added other factors. Heat and cold, rain and snow, along with the varying resistance of the rocks, increase the opportunities for erosion. The canyon walls crumble; the river acquires a cutting tool, tons of debris, rainfall running off the high plateau creates feeder streams that carve side canyons. Pushing slowly backward into the plateau, the side canyons expose new rocks, and the pattern of erosion continues.

6. What does the passage mainly discuss?

A. Patterns of erosion in different mountain ranges.

B. Forces that made the Grand Canyon.

C. The increasing pollution of the Colorado River.

D. The sudden appearance of the Grand Canyon.

7. In the first sentence, the author refers to the Grand Canyon as a “wound” to indicate that .

A. it was caused by some ancient convulsion

B. its presence is an embarrassment to the state of Colorado

C. it looks like an injury on the Earth's surface

D. it has caused many visitors to injure themselves.

8. According to the passage, the first phenomenon to contribute to the formation of the Grand Canyon was .

A. a series of volcanic eruptions