问题 单项选择题

采用条形荷载导出的地基界限荷载计算公式用于矩形底面基础设计时,其结果:

A.偏于安全

B.偏于危险

C.不能采用

D.安全度不变

答案

参考答案:A

解析:地基的临塑荷载、界限荷载公式均是在均布条形荷载的情况下导出的,由于相同宽度的条形荷载所引起的附加应力,其影响深度大于矩形和圆形荷载,所以矩形、圆形荷载借用这个公式计算,其结果偏于安全。

选择题
单项选择题

For many people today, reading is no longer relaxation. To keep up their work they must read letters, reports, trade publications, interoffice communications, not to mention newspapers and magazines: a never ending flood of words. In (1) a job or advancing in one, the ability to read and comprehend (2) can mean the difference between success and failure. Yet the unfortunate fact is that most of us are (3) readers. Most of us develop poor reading (4) at an early age, and never get over them. The main deficiency (5) in the actual stuff of language itself—words. Taken individually, words have (6) meaning until they are strung together into phrases, sentences and paragraphs. (7) , however, the untrained reader does not read groups of words. He laboriously reads one word at a time, often regressing to (8) words or passages. Regression, the tendency to look back over (9) you have just read, is a common bad habit in reading. Another habit which (10) down the speed of reading is vocalization—sounding each word either orally or mentally as (11) reads.

To overcome these bad habits, some reading clinics use a device called an (12) , which moves a bar(or curtain) down the page at a predetermined speed. The bar is set at a slightly faster rate (13) the reader finds comfortable, in order to "stretch" him. The accelerator forces the reader to read fast, (14) word by word reading, regression and subvocalization practically impossible. At first (15) is sacrificed for speed. But when you learn to read ideas and concepts, you will not only read faster, (16) your comprehension will improve. Many people have found (17) reading skill drastically improved after some training. (18) Charlie Au, a business manager, for instance. His reading rate was a reasonably good 172 words a minute(19) the training; now it is an excellent 1,378 words a minute. He is delighted that how he can (20) a lot more reading material in a short period of time.

第(17)空应选择()

A.our

B.your

C.their

D.other