问题 单项选择题

程序设计语言包括 (41) 等几个方面,它的基本成分包括 (42) 。Chomsky(乔姆斯基)提出了形式语言的分层理论,他定义了四类文法:短语结构文法、上下文有关文法、上下文无关文法和正则文法。一个文法可以用一个四元组G=(∑,V,S,P)表示,其中,∑是终结符的有限字符表,y是非终结符的有限字母表,S(∈V)是开始符号,P是生成式的有限非空集。在短语文法中,P中的生成式都是α→β甲的形式,其中α∈ (43) ,β∈(∑∪V)*。在上下文有关文法中,户中的生成式都是α12→α1βα2的形式,其中A∈ (44) ,β∈(∑∪V*),β≠。在上下文无关文法中,户中的生成式的左部∈ (45)

(44)处填()。

A.V

B.V+

C.

D.

答案

参考答案:A

阅读理解

阅读理解。

     The first English dictionary was published in 1604. The dictionary was actually nothing more than a list

of about 3, 000 difficult words, each followed by a one-word definition.

     The author, Robert Cawdrey, made no attempt to include everyday words in his dictionary. No one, he

reasoned, would ever have to look up a word in a dictionary if he already knew the meaning of the word.

During the 1600's more dictionaries were published. Each followed Cawdrey's lead and presented a few

thousand hard words. Around 1700 one dictionary maker, John Kersey, did define easy words as well as hard

words. But until the 1750's all the dictionaries were rather crude and not very valuable.

     A man named Dr Samuel Johnson changed all this. In 1755 Dr Johnson produced the first modern

dictionary. He included in his dictionary all important words, both easy and hard, and he gave good meanings.

He also gave good sentences to show how each word was actually used in speech and in writing. By the end

of the 1700's most dictionary makers had followed Johnson's example. Dictionaries were getting better and

better.

      The 1800's saw the greatest improvement in the quality of dictionaries. In England scholars planned and

prepared the Oxford English Dictionary, a twenty-volume (卷;册;部) work. One of the most interesting

features of the Oxford Dictionary is its word histories. It traces (追溯;探索) the history of each word from

its earliest recorded use up to the time of the printing of the dictionary.

1. The first English dictionary _______.

A. defined easy words as well as hard ones

B. was just a list of difficult words with one-word definitions

C. included a number of everyday words

D. was considered to be a very valuable one

2. According to the passage, before 1755 all English dictionaries _______.

A. were of no value

B. only defined hard words

C. defined both easy words as well as hard words

D. were far from being perfect

3. Which of the following statements is not true about Dr Johnson's dictionary?

A. It was not very valuable.

B. It was the first modern English dictionary.

C. It included easy words as well as hard ones.

D. It gave sentences to show the usage of words.

4. The most interesting feature of the Oxford Dictionary was that ______.

A. it had a complete list of difficult words

B. it gave sentences showing how each word was actually used

C. it was a 20-volume work

D. it showed the history of each word

5. This passage is mainly about _____.

A. the difference of English dictionaries

B. the origin of English dictionaries

C. the development of English dictionaries

D. the features of English dictionaries

单项选择题