问题 单项选择题

下面对控件的描述正确的是( )。

A.用户可以在组合框中进行多重选择

B.用户可以在列表框中进行多重选择

C.用户可以在一个选项组中选中多个选项按钮

D.用户对一个表单内的一组复选框只能选中其中一个

答案

参考答案:B

解析: 列表框可以在其中进行多重选定,而组合框不能进行此项操作,对于一个选项组来说只能选择一个选项,而复选框可以选择多个选项。

实验题

为研究锌和铝的金属活动性,某研究小组进行了如下探究。

(1)小明设计的实验方案:向表面积相同的铝片和锌粒中分别加入盐酸。写出锌与盐酸反应的化学方程式                                         

(2)小芳将去膜和未去膜的铝片分别放入盐酸中,发现前者比后者反应快,原因是     

                                                                                                        

(3)小芳在(2)实验中,还观察到有“灰黑色沉淀”这一异常现象出现。

【提出问题】铝与盐酸反应出现的灰黑色沉淀的组成是什么?

【查阅文献】铝在颗粒较小时为灰黑色;AlCl3为无色透明晶体或白色而微带浅黄色的固体,易溶于水和乙醇。

【提出合理假设】假设a:该灰黑色沉淀可能含有                         

假设b:该灰黑色沉淀可能含有AlCl3

假设c:该灰黑色沉淀可能含有难溶于酸的物质。

【设计并完成实验】取灰黑色沉淀分别进行如下实验。

实验编号实验操作实验现象
加入适量稀盐酸有微量气泡,固体全部溶解,得到澄清溶液
加入适量蒸馏水固体部分溶解
加入适量无水乙醇固体部分溶解
【得出结论】由实验①可判断假设c            (填“成立”或“不成立”),再集合②和③可得出该灰黑色沉淀的成分是                                   

(4)你认为①中小明的实验能否比较锌和铝的金属活动性强弱?              (填“能”或“不能”),分别从设计方法和操作可行性的角度,具体说明理由                   

                                                                           

阅读理解

阅读理解。

     The early 1900s were very different from today.Toys,though they have evolved in many

ways,were still the delight of children everywhere.

     Theodore Roosevelt's Presidency marks the beginning of the "Teddy Bear". In the year

1902,toy bears were named "Teddy" after the president's nickname.The Teddy Bear became

known worldwide,and is still known and loved today.It was only a few years later that the

Teddy Bears were mass produced.

     In 1913,an item called the Erector Set was invented.It was a steel,motorized toy that

children could use to build models of anything.Its creator was A.C.Gilbert,a medical doctor.

     Charles Pajeau created a similar wooden set called Tinker Toys in the year 1914.Tinker

Toys were made for younger children.

     Raggedy Ann dolls first came on the scene after newspaper cartoonist Johnny Gruelle

reproduced the doll he made for his daughter.That was in 1915.

     The following year,an architect's son named John Lloyd Wright,invented Lincoln Logs,

which were interlocked to make structures.

     Two years after Mickey Mouse was created,stuffed(填塞)Mickey Mouse dolls were

made by Charlotte Clark.This was the start of Disney merchandise.

     The yoyo became popular in the United States after Donald Duncan bought a yoyo

company in 1929.

     The ViewMaster,a three dimensional viewer,was developed by a camera enthusiast

named William Gruber.The toy became popular when Gruber licensed Disney characters

to make still,3D images from Disney movies and television programs.

      Finally,in 1940,model airplanes were mass produced.They started out as a way for

manufacturers to sell planes to the military,but later caught on as a toy.

     The toys that we know and love today have had their roots from these ancient times.

Isn't it interesting to know that if it hadn't been for all these creative people,most of the

games you know today would never have been?

1.Why were toy bears named "Teddy"?

A.To be suitable for mass production.

B.To be easily pronounced by children.

C.To meet the advertisers' needs.

D.To memorize President Theodore Roosevelt.

2.In which aspect do the toys created by Gilbert differ from those by Charles?

A.Shape.  

B.Material used.

C.Themes.  

D.Price.

3.When did the ViewMaster become popular?

A.After William Gruber was born.

B.After Gruber licensed Disney characters.

C.Two years after Mickey Mouse was created.

D.When Disney merchandise was started.

4.From the last paragraph we can learn that________.

A.those people who created these games should never be forgotten

B.some toys created in ancient times now disappear

C.creativity exists in every field all the time

D.toys nowadays are totally different from those in ancient times

5.What does the passage talk about?

A.The function of toys.

B.The history of Disney characters.

C.Toys in the early 1900s.

D.The financial meaning of toys.