问题 选择题

下列常用仪器的操作方法不正确的是(  )

A.用酒精灯外焰直接加热蒸发皿

B.打开试剂瓶取用试剂后及时盖瓶塞

C.给试管内固体加热,试管口略向下倾斜

D.取用试剂后将滴管清洗再放回原滴瓶

答案

A、蒸发皿可直接加热,故说法正确;

B、打开试剂瓶取用试剂后应及时盖好瓶塞,以防试剂被污染或变质,故说法正确;

C、给试管内固体加热,试管口略向下倾斜,以防冷凝水倒流到试管底部炸裂试管,故说法正确;

D、滴瓶上的滴管是专用的,不用清洗,故说法错误.

故选;D.

阅读理解

阅读理解

    It was a lovely sunny Saturday morning in early October. Jan Hunter sat out of the window of her room as she planned what she would do today. She would like to take Buster, her sheep, to the field for a short walk. Perky, her hamster (an animal like a mouse) and Slipper, her snake, would enjoy an outing too.

"I'll help you clean your room," Mrs. Hunter said. "Then you'll be free to do what you want the rest of the

day."

    Jan started picking up her clothes. Mrs. Hunter turned to the bed to take off the sheets (床单). As she

lifted the pillow( 枕头), Slipper moved quickly under the blanket(毯子).

    "That does it!" Mrs. Hunter cried. "Get that snake out of here! And look at this-one of your best shoes

too dirty to see the color. This is it. Jan. No more animals in the house; that's final!" Mrs. Hunter said in a

loud voice as she marched out of the room.

    Jan felt sad. She walked slowly across the street, Buster followed behind, to tell her tale to her old

friend Mr. Ward. He thought for a few minutes. Then he said that if Jan found the right cages(笼子) for

the pets, perhaps Mrs. Hunter could let the animals live out on the warm sun porch(门廊).

Jan remembered an old bird cage that would do for Perky. Buster's bed could simply be moved.

Something for Slipper, though, was a real problem.

    "Let's see what there is out in my garden," Mr. Ward suggested. They found a aquarium(鱼缸)in the

corner. Mr. Ward pulled out a large piece of glass that would do for a cover. Jan and Buster rushed

home to see what Mrs. Hunter would say.

    When Mr. Ward heard Jan's loud cry of joy, he knew Jan's troubles were over.

1. The story took place on_____________.

A. a cold day in March

B. a weekend day in October

C. a Saturday in September

D. a warm day in January

2. __________ is the most important character in the story.

A. Jan

B. Mrs. Hunter

C. Mr. Ward

D. Buster

3. What happened first in the story?

A. Jan took Buster for a walk.

B. Mrs. Hunter saw the dirty shoes.

C. Mrs. Hunter saw Slipper in Jan's room.

D. Jan told her sad story to her friend Mr. Ward.

4. What was the problem in the story?

A. Mrs. Hunter was afraid of snakes.

B. Mr. Ward had an aquarium in his garden.

C. Jan didn't know what to do in such good weather.

D. Jan's mother said the pets couldn't stay in the house.

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.training
B.habits
C.situations
D.custom