问题 阅读理解

David came from a poor family. When he finished his high school, however, he was given a wonderful present. “Some of my friends got new clothes and a rich boy even got a new car,” he remembered, “My dad reached into his trousers pocket and took something out. I held out my hand, and his present dropped into it — a nickel (五分镍币).”

Dad said to me, “Buy a newspaper with that. Read every word of it. Then turn to the classified section (分类栏目) and get yourself a job. Get into the world. It’s all yours now.” I always thought that was a great joke my father had played on me until a few years later when I was in the army, sitting in a foxhole (战壕), and thinking about my family and my life. It was then that I realized that my friends had got only new cars, or only new clothes. My father had given me the whole world. What a great present!

1. When David left school, he received ______ as a present.

A. a new car        B. new clothes         C. a newspaper     D. hardly anything

2. What did David become a few years later?

A. A college student.  B. A rich person.      C. A soldier.     D. A newspaper reporter.

3. The title of the passage may be ______.

A. How to be a Soldier  B. How to find a Job    C. A Great Joke D. A Great Present

答案

小题1:D

小题1:C

小题1:D

小题1:根据I held out my hand, and his present dropped into it — a nickel (五分镍币).”描述可知几乎没得到什么礼物,故选D。

小题1:根据a few years later when I was in the army,可知他成为了一名战士,故选C。

小题1:根据短文最后一句话My father had given me the whole world. What a great present!及上文描述可知选D。

实验题

小娜及学习小组的同学在老师的指导下对黄铜中铜和锌的含量及其性质展开了探究。

【查阅资料】

HCl+AgNO3=AgCl ↓+HNO3,AgCl 是一种白色沉淀,这个反应在化学上用于检验和鉴别。

【提出问题】测定黄铜中锌、铜的质量分数。

【实验原理及实验方案设计】(略)。

Ⅰ【探究实验】

1. 先将黄铜在热碱液中浸泡一段时间,以除去表面的油污。然后再放在稀盐酸中浸泡片刻,其目的是_________________________ 。用蒸馏水清洗干净,干燥,取少量研碎,称取质量为ag 。

2. 将ag 试样放入小烧杯中,加入足量稀盐酸,搅拌使其充分反应。

3. 将小烧杯中的混合物过滤,_____________( 请将此实验步骤补充完整) 。

4. 称取固体的质量为bg 。

5. 计算出黄铜中锌和铜的质量分数。

Ⅱ【反思与评价】 在步骤1 中,若试样用蒸馏水洗涤之后,不干燥,则计算出合金中锌的质量分数将                (填“偏大”、“偏小”或“不受影响”)

Ⅲ【拓展探究】

1. 重复【探究实验】步骤1 。

2. 将ag 试样放入一定量的硝酸银溶液中,使其充分反应后过滤,得到固体和蓝色滤液,并对滤液的组成进行探究。

(1 )锌和硝酸盐溶液反应的化学方程式是________________________ 。

(2 )同学们对蓝色滤液中所含的溶质做出多种猜想,其中只有两种猜想可能成立,这两种猜想是:①溶质为硝酸锌和硝酸铜;②溶质为______________ 。

(3 )设计两种实验方案来验证以上猜想。 

单项选择题