问题 选择题

下列现象不是由分子运动产生的是(  )

A.月季花是我市的市花.月季花盛开的时候,花香四溢

B.冬天虽然温度很低,但晾在外面的衣服仍然能够干

C.把红墨水滴入盛有水的烧杯中,静置后烧杯中水都变红了

D.V1mL水和V2 mL酒精混合得VmL溶液,则V1+V2>V

答案

A、月季花盛开的时候,花香四溢,是因为花香分子不停地做无规则的运动,扩散到空气中,所以人们闻到了花香,故不符合题意;

B、冬天虽然温度很低,但晾在外面的衣服仍然能够干,是因为水分子不停地做无规则的运动,扩散到空气中,故不符合题意;

C、红墨水滴入盛有水的烧杯中,静置后烧杯中水都变红了,是因为分子不停地做无规则的运动,因此,烧杯中水都变红了,故不符合题意;

D、V1mL水和V2 mL酒精混合得VmL溶液,则V1+V2<V,混合后溶液体积发生变化是因为分子之间有间隔,不是由分子运动引起的,所以故D选项符合题意;

故选D.

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.scales
B.cuts
C.slows
D.measures

单项选择题