单选题Although the first part of the book is easy, the rest ______A are difficultB have been found difficultC is supposed difficultD has proved difficult

However,it has been found that even people insensitive to a certain smell at first can suddenly become sensitive to it when（ ）to it often enough.

A.subjected
B.left
C.drawn
D.exposed

Deep inside a mountain near Sweetwater in East Tennessee is a bady?of water known as the Lost?Sea.It is listed by the Guinness Book of World Records as the world′s largest underground lake.The Lost Sea is part of an extensive and historic cave system called Craighead Caverns.
The caverns have been known and used since the days of the Cherokee Indian nation.The cave?expands into a series of huge rooms from a small opening on the side of the mountain.Approximately?one mile from the entrance,in a room called-The Council Room",many Indian artifacts have been?found.Some of the items discovered include pottery,arrowheads,weapons,and jewelry.
For many years there were persistent rumors of a large underground lake somewhere in a cave,but it was not discovered until 1905.In that year,a thirteen-year-old boy named Ben Sands crawled through a small opening three hundred feet underground.:He found himself in a large cave half filled?with water.
Today tourists visit the Lost Sea and ride far out onto it in glass-bottomed boats powered by electric motors.More than thirteen acres of water have been mapped out so far and still no end to the lake has been found.Even though teams of divers have tried to explore the Lost Sea,the full extent
of it is still unknown.

The Lost Sea is unique because it is__________.

A.part of a historical cave system
B.the biggest underground lake in the world
C.listed in the Guinness Book of World Records
D.the largest body of water in Tennessee

共用题干
Some Things We Know About Language
Many things about language are a mystery,and many will always remain so.But some things we do know.
First , we know that all human beings have a language of some sort.There is no race（种族）of men anywhere on earth so backward that it has no language,no set of speech sounds by which the people communicate with one another.Furthermore,in historical times,there has never been a race of men without a language. Second,there is no such thing as a primitive（原始的）language.There are many people whose cultures are undeveloped,who are,as we say,uncivilized,but the languages they speak are not primitive.In all known languages we can see complexities that must have been tens of thousands of years in developing. This has not always been well understood;indeed,the direct contrary has often been stated.Popular ideas of the language of the American Indians will illustrate.Many people have supposed that the Indians communicated in a very primitive system of noises.Study has proved this to be nonsense.There are,or were, hundreds of American Indian languages,and all of them turn out to be very complicated and very old.They are certainly different from the languages that most of us are familiar with,but they are no more primitive than English and Greek.
A third thing we know about language is that all languages are perfectly adequate.That is,each one is a perfect means of expressing the culture of the people who speak the language. Finally,we know that language changes.It is natural and normal for language to change;the only languages which do not change are the dead ones.This is easy to understand if we look backward in time. Change goes on in all aspects of language.Grammatical features change as do speech sounds,and changes in vocabulary are sometimes very extensive and may occur very rapidly.Vocabulary is the least stable part of any language.

The author has used American Indian language to illustrate______.
A:it hasn't been well understood that there is no primitive language
B:the Indians communicated in a very primitive system of noises
C:English and Greek are less primitive than American Indian languages
D:hundreds of American Indian languages are easy and young

my frienD tolD me that( )
A the English language is diffiCult
B English is diffiCult
C the English is diffiCult
D what English is diffiCult

We have been through some rough times together.

A:long
B:happy
C:difficult
D:short

共用题干
Some Things We Know About Language
Many things about language are a mystery,and many will always remain so.But some things we do know.
First,we know that all human beings have a language of some sort. There is no race of men anywhere on earth so backward that it has no language,no set of speech sounds by which the people communicate with one another. Furthermore,in historical times,there has never been a race of men without a language.
Second,there is no such thing as a primitive language.There are many people whose cultures are undeveloped,who are,as we say,uncivilized,but the languages they speak are not primitive .In all known languages we can see complexities that must have been tens of thousands of years in developing.
This has not always been well understood;indeed,the direct contrary has often been stated.
Popular ideas of the language of the American Indians will illustrate.Many people have supposed that the Indians communicated in a very primitive system of noises.Study has proved this to be nonsense .There are,or were,hundreds of American Indian languages,and all of them turn out to be very complicated and very old.They are certainly different from the languages that most of us are familiar with,but they are no more primitive than English and Greek.
A third thing we know about language is that all languages are perfectly adequate. That is, each one is a perfect means of expressing the culture of the people who speak the language.
Finally,we know that language changes.It is natural and normal for language to change;the only languages which do not change are the dead ones.This is easy to understand if we look backward in time.Change goes on in all aspects of language.Grammatical teatures change as do speech sounds,and changes in vocabulary are sometimes very extensive and may occur very rap-idly. Vocabulary is the least stable part of any language.

According to the author,language changes are most likely to occur in______.
A: grammar
B: pronunciation
C: vocabulary
D: intonation