The term “Ice Age“ may give a wrong impression. The epoch that geologists know as the Pleistocene and that spanned the 1.5 to 2. 0 million years prior to the current geologic epoch was not one long continuous glaciation, but a period of oscillating climate with ice advances punctuated by times of interglacial climate not very different from the climate experienced now. Ice sheets that derived from an ice cap centered on northern Scandinavia reached southward to Central Europe. And beyond the margins of the ice sheets, climatic oscillations affected most of the rest of the world; for example, in the deserts, periods of wetter conditions(pluvials)contrasted with drier, interpluvial periods. Although the time involved is so short, about 0. 04 percent of the total age of the Earth, the amount of attention devoted to the Pleistocene has been incredibly large, probably because of its immediacy, and because the epoch largely coincides with the appearance on Earth of humans and their immediate ancestors. There is no reliable way of dating much of the Ice Age. Geological dates are usually obtained by using the rates of decay of various radioactive elements found in minerals. Some of these rates are suitable for very old rocks but involve increasing errors when used for young rocks; others are suitable for very young rocks and errors increase rapidly in older rocks. Most of the Ice Age spans a period of time for which no element has an appropriate decay rate. Nevertheless, researchers of the Pleistocene epoch have developed all sorts of more or less fanciful model schemes of how they would have arranged the Ice Age had they been in charge of events. For example, an early classification of Alpine glaciation suggested the existence there of four glaciations, named the Gunz, Mindel, Piss, and Wurm. This succession was based primarily on a series of deposits and events not directly related to glacial and interglacial periods, rather than on the more usual modern method of studying biological remains found in interglacial beds themselves interstratified within glacial deposits. Yet this succession was forced willy-nilly onto the glaciated parts of Northern Europe, where there are partial successions of true glacial ground moraines and interglacial deposits, with hopes of ultimately piecing them together to provide a complete Pleistocene succession. Eradication of the Alpine nomenclature is still proving a Herculean task. There is no conclusive evidence about the relative length, complexity, and temperatures of the various glacial and interglacial periods. We do not know whether we live in a postglacial period or an interglacial period. The chill truth seems to be that we are already past the optimum climate of postglacial time. Studies of certain fossil distributions and of the pollen of certain temperate plants suggest decreases of a degree or two in both summer and winter temperatures and, therefore, that we may be in the declining climatic phase leading to glaciation and extinction.

In the passage, the author is primarily concerned with______.

A．searching for an accurate method of dating the Pleistocene epoch

B．discussing problems involved in providing an accurate picture of the Pleistocene epoch

C．declaring opposition to the use of the term “Ice Age“ for the Pleistocene epoch

D．criticizing fanciful schemes about what happened in the Pleistocene epoch

The “wrong impression“(line 1.)to which the author refers is the idea that the______.

A．climate of the Pleistocene epoch was not very different from the climate we are now experiencing

B．climate of the Pleistocene epoch was composed of periods of violent storms

C．Pleistocene epoch consisted of very wet, cold periods mixed with very dry, hot periods

D．Pleistocene epoch comprised one period of continuous glaciation during which Northern Europe was covered with ice sheets

Which of the following does the passage imply about the “early classification of Alpine glaciation“?

A．It should not have been applied as widely as it was.

B．It represents the best possible scientific practice, given the tools available at the time.

C．It was a valuable tool, in its time, for measuring the length of the four periods of glaciation.

D．It could be useful, but only as a general guide to the events of the Pleistocene epoch.

The author refers to deserts primarily in order to______.

A．support the view that we are probably living in a postglacial period

B．illustrate the idea that what happened in the deserts during the Ice Age had far-reaching effects even on the ice sheets of Central and Northern Europe

C．illustrate the idea that the effects of the Ice Age’s climatic variations extended beyond the areas of ice

D．support the view that during the Ice Age sheets of ice covered some of the deserts of the world

There is nothing in physical structure, the brain or the internal organs to______a difference. display indicate demonstrate appear

This kind of material can______heat and moisture. delete compel constrain repel

Government loan have been the______of several shaky business companies. tornado salvation delinquency momentum

While she had the fever, she______for hours. raved sniggered tittered perforated

______seen by anyone, the thief escaped. Being not Not being To be Be not

We are making good progress, but we must not______until we have achieved our objective. let up give up put up draw up

Our civilization cannot be thought of as______in a short period of time. to have been created to be created having been created being created

Their coach must______the team’s poor performance. answer for answer to answer back answer about

The term “Ice Age“ may give a wrong impression. The epoch that geologists know as the Pleistocene and that spanned the 1.5 to 2. 0 million years prior to the current geologic epoch was not one long continuous glaciation, but a period of oscillating climate with ice advances punctuated by times of interglacial climate not very different from the climate experienced now. Ice sheets that derived from an ice cap centered on northern Scandinavia reached southward to Central Europe. And beyond the margins of the ice sheets, climatic oscillations affected most of the rest of the world; for example, in the deserts, periods of wetter conditions(pluvials)contrasted with drier, interpluvial periods. Although the time involved is so short, about 0. 04 percent of the total age of the Earth, the amount of attention devoted to the Pleistocene has been incredibly large, probably because of its immediacy, and because the epoch largely coincides with the appearance on Earth of humans and their immediate ancestors. There is no reliable way of dating much of the Ice Age. Geological dates are usually obtained by using the rates of decay of various radioactive elements found in minerals. Some of these rates are suitable for very old rocks but involve increasing errors when used for young rocks; others are suitable for very young rocks and errors increase rapidly in older rocks. Most of the Ice Age spans a period of time for which no element has an appropriate decay rate. Nevertheless, researchers of the Pleistocene epoch have developed all sorts of more or less fanciful model schemes of how they would have arranged the Ice Age had they been in charge of events. For example, an early classification of Alpine glaciation suggested the existence there of four glaciations, named the Gunz, Mindel, Piss, and Wurm. This succession was based primarily on a series of deposits and events not directly related to glacial and interglacial periods, rather than on the more usual modern method of studying biological remains found in interglacial beds themselves interstratified within glacial deposits. Yet this succession was forced willy-nilly onto the glaciated parts of Northern Europe, where there are partial successions of true glacial ground moraines and interglacial deposits, with hopes of ultimately piecing them together to provide a complete Pleistocene succession. Eradication of the Alpine nomenclature is still proving a Herculean task. There is no conclusive evidence about the relative length, complexity, and temperatures of the various glacial and interglacial periods. We do not know whether we live in a postglacial period or an interglacial period. The chill truth seems to be that we are already past the optimum climate of postglacial time. Studies of certain fossil distributions and of the pollen of certain temperate plants suggest decreases of a degree or two in both summer and winter temperatures and, therefore, that we may be in the declining climatic phase leading to glaciation and extinction.

Beene’s new novel proves he isn’t just a______in the pan. flare glitter spark flash

The newly-built Science Building seems______enough to last a hundred years. spacious sophisticated substantial steady

The political future of the president is now hanging by a______. thread cord string rope

The speaker______us with tales of exotic lands and buried treasure. detoured offset tantalized ushered

On August 18th the president announced a general______for political exiles. ado yoga quartet amnesty

If it doesn’t rain within the next few weeks, the crops will have to be watered if they are______. to survive to be survived being survived surviving

She refused to______the car key to her husband until he had promised to wear his safety belt. hand in hand out hand down hand over

The fossilized remains of a type of camel______a dog have been found in the Badlands of South Dakota. no more larger than not larger than no larger than which no larger than

Perhaps the most significant postwar trend was the decentralization of cities throughout the United States, ______ when massive highway-building programs permitted greater suburban growth. and accelerated a phenomenon a phenomenon that accelerated accelerating a phenomenon which the acceleration of which phenomenon

______by the United States government’s Bureau of Labor Statistics, the Consumer Price Index compares current costs of goods and services with past costs. To prepare As it prepared When preparation Prepared

As the train will not leave until one hour later, we______grab a bite at the snack bar. may well just as well might as well as well

In the passage, the author is primarily concerned with______.

The “wrong impression“(line 1.)to which the author refers is the idea that the______.

Which of the following does the passage imply about the “early classification of Alpine glaciation“?

The author refers to deserts primarily in order to______.

The author would regard the idea that we are living in an interglacial period as______.