问题 选择题

近日,天涯论坛上一篇“镶镍铬烤瓷牙有可能引发肾病?”的帖子引发了人们对镍铬烤瓷牙安全性的质疑.镍铬烤瓷牙主要由镍铬合金和陶瓷两种材料加工而成.这两种材料分别属于(  )

A.复合材料、金属材料

B.金属材料、无机非金属材料

C.无机非金属材料、合成材料

D.合成材料、金属材料

答案

答案:B

问答题 简答题
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 172words 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.

A.for
B.in
C.after
D.before