中山2021年4月自考英语(一)复习（45）

主要语言点

1.At the beginning of the twentieth century， there were four powerful means of transmitting and receiving information over long distances：…

本句中的beginning 是一个名词，意思是“开始，开端”。如：

means在本句中的意思是“方法;工具”

by all means 尽一切办法

live within/beyond one's means 量入(不量入)为出

a means to an end 达到目的的方法

by some means or other 用某种方法

2.By the middle of the century， both radio and television had become established means of transmitting sounds and pictures.

句中所用的过去完成时，表示过去某时前已经发生的动作或情况。该动作已经完成，或者可能延续下去。用by引起的时间状语常与过去完成时连用。例如：

1)By the end of last June， they had visited 15 countries. (到去年六月底为止他们已经访问了15个国家。)

2)By the end of last year Henry had collected 1500 butterfly specimens. (到去年年底，亨利已经采集了一千五百多个蝴蝶标本。)

established在句中做形容词，意思是“常规的”。这个词还可解释为“(被)设立的;确认的;既定的;公认的”。例如：

1)a newly established organization (新设的组织)

2)the established principles of international law (公认的国际法准则)

3)an established fact (既成事实)

4)an established custom (常规)

3.In order to transmit an event such as the Olympics Via satellite， television signals are first changed into radio waves，which are then sent from a station on earth to an orbiting satellite.

such as的后面既可以跟名词也可以跟从句，意为“诸如…之类的”;“例如”或“像…这样的人或事物”

which引导的是一个非限定性的定语从句。非限定性定语从句在修饰人时用who， whom或whose， 在修饰物时用which.非限定性定语从句常用逗号与主句分开

非限定性定语从句也可用关系副词where或when来引导。非限定性定语从句的先行词可以是一个词，也可以是前面主句中的一个短语、从句或前面整个句子，通常用关系代词which引导。

4.In theory， every person will have access to an unlimited amount of information.

in theory意为“从理论上来说;在理论上”，与其意思相反的词组是in practice (在实践中;实际上)。

have access to是一个很常用的词组，意为“可接近，可进入”，to是介词，动词have也可用其他词替换。如get，gain，give，win等。

information是一个不可数名词，后面不可以加s，许多信息可以用a lot of information， a large amount of information， much information等表达。一条信息可以表达为a piece of information.

amount通常用在不可数名词前面，如the amount of money; a considerable amount of prejudice (相当大的偏见)。在复数名词前面可用number，如the number of mistakes; the number of students