问题 阅读理解

Today, roller skating is easy and fun. But many years ago, it wasn’t easy at all. Before 1750, people never tried skating on wheels. That changed because of a man named Joseph Merlin. Merlin’s work was making instruments. In his free time he liked to play the violin. Merlin was a man with many ideas and many dreams. People called him a dreamer.

One day Merlin received an invitation to go to an important party. He was very pleased and a little excited. As the day of the party came near, Merlin began to think. He wanted to find a way to make a wonderful entrance at the party. Merlin had an idea. He thought that he would attract a lot of attention if he could skate into the room.

Merlin tried different ways to make himself roll. Finally, he decided to put two wheels under each shoe. These were the first roller skate shoes. Merlin was very proud of them. He dreamed of arriving at the party and skating into the room while playing the violin. He was sure that everyone would be very surprised.

On the night of the party Merlin rolled into the room, playing his violin. Everyone was really surprised to see him. There was just one problem. Merlin had no way to stop his roller skating. He rolled on, playing the violin. Then, with all eyes on him, Merlin hit into a huge mirror on the wall. The mirror broke into many pieces with a very loud noise. But nobody forgot Merlin’s wonderful entrance after that.

小题1:The story tells us that people began to enjoy roller-skating _______.          

A.before the year 1750

B.before the invitation

C.because of Joseph Merlin

D.because it was dangerous小题2:People called Merlin a dreamer because ___________.        

A.he slept and dreamed a lot

B.he was full of different ideas

C.he was a talented violinist

D.he always made people’s dreams come true小题3:___________ made Merlin think of skating on wheels.

A.Merlin’s work

B.Merlin’s violin

C.A huge mirror

D.An important party小题4:What was Merlin’s problem after he rolled into the room?

A.He couldn’t stop his roller-skating.

B.He couldn’t attract a lot of attention.

C.Everyone was surprised at him.

D.He couldn’t play the violin while rolling.小题5:The text is mainly about_________.

A.a strange man

B.an unusual party

C.how roller skating began

D.how people enjoyed themselves in the 18th century

答案

小题1:C

小题1:B

小题1:D

小题1:A

小题1:C

单项选择题
实验题

硫酸亚铁晶体(FeSO4·7H2O)在医药上作补血剂。某课外小组测定该补血剂中铁元素的含量。实验步骤如下:

请回答下列问题:

(1)证明步骤①滤液中含有Fe2+的方法是先滴加KSCN溶液,再滴加            ,该过程的现象为:                 

(2)步骤②加入过量H2O2的目的:                   

(3)步骤③中反应的离子方程式:                            

(4)步骤④中一系列处理的操作步骤:过滤、         、灼烧、         、称量。

(5)若实验无损耗,则每片补血剂含铁元素的质量         g。

(6)该小组有些同学认为用KMnO4溶液滴定也能进行铁元素含量的测定。

(5Fe2++MnO4+8H+→5Fe3++Mn2++4H2O)

①实验前,首先要精确配制一定物质的量浓度的KMnO4溶液250mL,配制时需要的仪器除天平、玻棒、烧杯、胶头滴管外,还需               

②上述实验中的KMnO4溶液需要酸化,用于酸化的酸是         

a.稀硝酸   b.稀硫酸    c.稀盐酸    d.浓硝酸

③滴定到终点时的颜色为         色。

(7)正常人每天应补充14mg左右的铁。其中绝大部分来自于食物。如果全部通过服用含FeSO4·7H­2­O的片剂。来补充铁,则正常人每天服需用含           mgFeSO4·7H2O为片剂。