问题 填空题

选择合适操作或仪器的序号填空.

①坩埚钳   ②搅拌   ③10.0mL量筒  ④50.0mL量筒  ⑤加热

(1)将浓硫酸注入水中,为使热量及时散发应     

(2)转移热的蒸发皿到石棉网上用      

(3)除去Na2CO3固体中的NaHCO3,操作是      

(4)量取8.8mL的H2O,应选择      

答案

(1)②;(2)①;(3)⑤;(4)③.

题目分析:(1)稀释浓硫酸时,要把浓硫酸缓缓地沿器壁注入水中,同时用玻璃棒不断搅拌,以使热量及时地扩散.

(2)正在加热的蒸发皿温度较高,为防止烫伤手,不能用手直接拿热的蒸发皿,应用坩埚钳夹取.

(3)碳酸氢钠在加热条件下生成碳酸钠、水和二氧化碳,能除去杂质且没有引入新的杂质,符合除杂原则.

(4)选取量筒时,尽量选用能一次量取的最小规格的量筒.量取8.8mL的H2O,应选择10.0mL量筒.

点评:本题难度不大,熟悉各种仪器的用途及使用注意事项、掌握常见化学实验基本操作的注意事项是解答此类试题的关键.

完形填空

阅读短文, 按照题目要求用英语回答问题。

Last December, Doris Low turned 90. Once a week she still drives to the Canadian National Institute for the Blind (CNIB) in Toronto, where she helps transform literature into Braille() to bring the power of story and knowledge to the hears and minds of blind readers. She has been volunteering her time and talents to such enterprises foe more than 40 years.

After working in the business world for a while, Low got fed up. So she turned to teaching at a technical school and later moved into the library.

Low’s mother liked reading. As her eyes began to fail, low read to her. Then “ hearing an advertisement encouraging people to learn Braille, I decided to give it a try.” In 1973, she was certified as a braille transcriber (转译者) and began transcribing books as a volunteer for the CNIB library.

The job was strenuous ---she could get to the end of a page, make a mistake on the last line, and have to do the whole thing again. For a number of years, low also worked in the CNIB sound studio reading books onto tape. Three years ago, she took up proofreading (校对) at the CNIB’s word factory.

In April, during Volunteer Week, the CNIB recognized Low for her great contributions. Thanks to volunteers like Low, the CNIB library has got more than 80,000 accessible materials for people unable to read traditional print. “ I can’t imagine how many readers of all ages have benefited from

Doris’s contribution as a skilled volunteer through her rich voice and her high degree of accuracy in the hundreds of books she has brailled and proofread over the years--- and she is still doing so,” said a CNIB official.

“For me,” said Low, “the CNIB is more than just a place to volunteer. Three thins matter most in my life: a little play, a little work, a little love. I’ve found them all here.”

小题1:What does Low still do at the age of 90 at the CNIB? ( no more than 10 words)

小题2:Why did Low learn Braille? ( no more than 15 words)

小题3:what does the underlined word “strenuous” most probably mean?(1 word)

小题4:What are Low’s contributions to the CNIB? ( no more than 10 words)

小题5:What do you think of Low? Give your reasons. ( no more than 20 words)

多项选择题 案例分析题