问题 选择题

下列各选项中物理原理不同于其他三项的是(  )

A.远处隆隆的雷声预示着可能有一场大雨

B.铁路工人用铁锤敲击钢轨,判定螺栓是否松

C.超声波洗牙

D.有经验的人选瓷碗总是敲一敲分辨音质

答案

A、根据雷声就可以判断要下雨,这是利用声音能传递信息;

B、铁路工人用铁锤敲击铁轨时,螺栓松动改变了物体细微处的结构,那么根据它们发出声音的音色不同,就可以判断出螺栓有无松动,这就说明了声音可以传播信息.

C、因为声音可以传播能量,并且超声波的频率很高,超声波之所以能洁牙就是利用超声波高频冲击;

D、好的瓷器组织结构紧密,密度大,敲击时发出像金属钢管被敲击时发出的声音.而组织结构松散,有裂纹的瓷器,在同样敲击时发出的声音沙哑短促.因此它们在敲击时发出声音的音色不同.所以,人们在挑选瓷器时,总是要轻轻地敲一敲,听一听,这是利用声音能传递信息;

故选C.

完形填空

Read the following text and choose the most suitable heading from A-F for each paragraph. There is on e extra heading which you do not need.

小题1:

You’re probably most familiar with college dictionaries, often called abridged dictionaries. Although abridged means “shortened”, these dictionaries contain more than 150.000 entries and provide detailed definitions that are sufficient for most college students and general users. College dictionaries also contain separate lists of abbreviations. Biographical and geographical names, foreign words and phrases. And tables of measures. Webster’s Ⅱ New Riverside University Dictionary and the American Heritage Dictionary of the English Language are college dictionaries.

小题2:

unabridged dictionaries contain as many as 500,000 entries and provide detailed definitions and extensive word histories (etymologies). These dictionaries, possibly in several volumes and mostly found in libraries, are excellent sources for scholarly inquiries. Unabridged dictionaries include the Oxford English Dictionary and the Random House Dictionary of the English Language.

小题3:

A dictionary entry has many elements: multiple definitions, syllabication, preferred spelling and pronunciation (some word have more than one acceptable spelling and pronunciation), and part-of-speech labels. Some entries also include plurals and capitalized forms. Synonyms, antonyms, and derivatives. Americanisms and etymologies may be provide along with usage notes, cross-references, and idioms.

小题4:

If you prefer using the dictionary on a computer, you can obtain CD-ROM versions of many major dictionaries. In addition, you can access numerous dictionaries, such as WWWebster’s Dictionary, on the Internet. Online dictionaries allow you to enter a search word (you even get help with spelling ) to see a definition, and sometimes even an illustration. Online dictionaries also offer additional features, such as word games. Language tips, and amusing facts about words. Some online dictionary services allow you to access numerous dictionaries, both general and specialized, in on search.

小题5:

Specialized dictionaries provide in-depth information about a certain field. For example there are dictionaries for the specialized vocabularies of law, computer technology, and medicine. In addition, there are dictionaries of synonyms, clichés, slang, and even regional expressions. Such as the Dictionary of American Regional English(DARE). There are also dictionaries of foreign languages, famous people’s names, literary characters’ names and place names.

单项选择题