问题 单项选择题

将软土地基表层的一定厚度的"硬壳层"作为地基持力层时,比较合理的基础方案是()。

A.素混凝土扩展基础

B.砖和毛石基础

C.灰土和三合土基础

D.钢筋混凝土扩展基础

答案

参考答案:D

阅读理解

阅读理解。

     Washington D.C. is the capital of the United States. It's the center of national government. It's a busy, working city with a large population. But what is more, Washington is also a city of history and culture. It is

  home to many famous and interesting public buildings and monuments, many of which are connected with

  the federal government.    

     Washington was created in 1790, when Congress (the highest lawmaking body of the United States)

  decided to place the nation's new capital in the east of the country. It was built half way between the

 northern and southern states of America. And of course it was named after George Washington, the first

 President of the United States.

     There are many tourist sights in Washington. Perhaps the most important tourist sight is the Capital

 Building. This is the house of the Congress. Another world-famous building in Washington is the White

 House. This is the home and office of the President of the United States. Most visitors are, however,

  surprised by how small the White House actually is.

     Washington is also a great cultural city. The Library of Congress contains one of the largest library

  collections in the world. The Smithsonian Museum holds the nation's largest collection of cultural

 materials. And the John F. Kennedy Center is a famous center of art and culture. It has many great

 musical and theatre performances throughout the year.

1. From the passage we know that Washington is situated in _____.

    A. the east, on the middle point from north to south of the country

    B. the center of the U. S. A.

    C. the east of the U. S. A.

    D. the east and halfway away from the north

2. The passage mentions _____ buildings.

    A. six    

    B. five  

    C. four      

    D. three

3. The writer introduces Washington in order of _____.

    A. population, history and culture  

    B. history and culture

    C. general introduction, history, sights and culture

    D. general introduction, history, sights, buildings and culture

问答题

根据下列材料,按要求完成任务。

材料一《义务教育化学课程标准(2011年版)》的内容标准:了解吸附、沉降、过滤和蒸馏等净化水的常用方法。

材料二教科书的知识结构体系

绪言化学使世界变得更加绚丽多彩

第一单元走进化学世界

第二单元我们周围的空气

第三单元物质构成的奥秘

第四单元自然界的水

课题1水的组成

课题2分子和原子

课题3水的净化

课题4爱护水资源

拓展性课题最轻的气体

第五单元化学方程式

第六单元碳和碳的氧化物

第七单元燃料及其利用

第八单元金属和金属材料

第九单元溶液

第十单元酸和碱

第十一单元盐化肥

第十二单元化学与生活

材料三教科书《水的净化》所呈现的内容。

课题3水的净化

纯水是无色、无臭、清澈透明的。而自然界的河水、湖水、井水、海水等天然水里由于含有许多可溶性和不溶性杂质,因此常呈浑浊(如图3-14)。

城市中的生活用水是经自来水厂净化处理过的。而在某些乡村,则利用明矾溶于水后生成的胶状物对杂质的吸附,使杂质沉降来达到净水的目的。

活动与探究

取3个烧杯,各盛大半烧杯浑浊的天然水(湖水、河水或井水等),向其中2个烧杯中各加入3药匙明矾粉末,搅拌溶解后,静置,观察现象。

再取一张圆形滤纸,如图3-16所示折好并放入漏斗,使之紧贴漏斗壁,并使滤纸边缘略低于漏斗口,用少量水润湿滤纸并使滤纸与漏斗壁之间不要有气泡。

如图3-17所示,架好漏斗,使漏斗下端管口紧靠烧杯内壁,以使滤液沿烧杯壁流下。

取上面处理过的一杯液体,沿玻璃棒慢慢向漏斗中倾倒,注意液面始终要低于滤纸的边缘。比较未经处理的天然水和做了不同程度处理的水,它们的清澈程度有什么差别?可以利用什么物品代替实验室中的滤纸和漏斗来过滤液体?

任务:

(1)试确定本节课的三维教学目标。

(2)试确定本节课的教学重点和难点。

(3)请用教学流程图的形式表示出你对本课的教学设计。

(4)实验室过滤操作中应该注意哪些问题?

(5)请对本节课进行板书设计。