问题 单项选择题

用于科学计算的计算机中,标志系统性能的主要参数是( )。

A.主时钟频率

B.主存容量

C.MFLOPS

D.MIPS

答案

参考答案:D

解析:主时钟频率和主存容量越大,系统的性能越高,但不是标志性的参数。MFLOPS是每秒百万个浮点操作.是衡量计算机系统的主要参数之一;MIPS是每秒处理的百万级的机器语言指令数,是衡量CPU速度的一个指标。

单项选择题
单项选择题

There (1) not one type of reading but several according to your reasons for reading. To read carefully, you have to (2) your reading speed and technique (3) your aim (4) reading. Skimming is a technique necessary for quick and efficient reading.

When skimming, you (5) the reading (6) quickly in order to get the (7) of it, to know how it is organized, (8) an idea of the tone or the intention of the writer. Skimming is (9) an activity which (10) an overall view of the text and (11) a definite reading competence.

Skimming doesn’t need reading all the material, but it doesn’t mean that it is an (12) skill for the lazy, because it need a high degree of alertness and concentration.

When you read, you usually start with (13) understanding and move towards detailed understanding rather than working the other way round. But (14) is also used after you have already carefully studied and you need to (15) the major ideas and concepts.

In order to be able to skim quickly and (16) through a text, you should know where to look for what you want. In preview skimming you read the introductory information, the headings and subheadings, and the summary, if one is provided. (17) this skimming, decide whether to read the material more thoroughly, and select the appropriate speed (18) you read.

The same procedure (19) for preview skimming could also be used to get an overview. Another method would be to read only key words. This is done by omitting the unnecessary words, phrases, and sentences.

In order to skim efficiently and fulfill your purpose, (20) practice is necessary.

17().

A.When

B.As

C.After

D.Before