问题 阅读理解

I went home one Saturday afternoon in the autumn of 1993 to get some work done in the garden. While sweeping leaves on the ground, my five-year-old son Nick came over and asked me to write something on a piece of paper to make a sign for him.

"What for?" I asked.

" I’m going to sell some of my stones, " he answered.

Nick was fascinated with stones and had collected many stones from all over.

" I’m too busy to do that for you. Go and ask your mum for help," I said.

A short time later, Nick, returned with a sign, reading, " Stones, One Dollar Each". He took the sign, a small chair and 4 of his best stones and walked to the road in front of our garden. There he put the stones in a line and sat down on the chair.

After half an hour, nobody passed by. I walked to him and asked him to go back, but he didn’t.

Another half hour later, a small car came down the road. I watched as Nick stood up, holding his sign up. A woman rolled down a window and read the sign. I couldn’t hear their talk, but I saw the woman turn to the driver and the man reach for his pocket.

I sat in the yard, as Nick ran to me. Waving the dollar, he shouted, "I told you I could sell one stone for a dollar -- if you believe in yourself, you can do anything. "

小题1:Why didn’t the writer help his son?

A.Because his wife is better at making a sign.

B.Because he didn’t know what to write.

C.Because he was busy sweeping leaves.

D.Because he didn’t want his son to sell the stones.小题2:The underlined words "was fascinated with" mean _________.

A.was far from

B.was afraid of

C.was famous for

D.was interested in小题3:Nick was a boy ___________.

A.who was kind

B.who had a strong mind

C.who was honest

D.who had many hobbies小题4:Which is the best title(题目) of the story?

A.My son’s first sale.

B.Let’s collect stones.

C.How to sell a stone.

D.A hobby that can make you rich.小题5:From the passage we know______________.

A.the story happened in spring

B.the car was driven by a woman

C.Nick spent half an hour selling one stone

D.the writer might be moved(感动)by his son

答案

小题1:C

小题1:D

小题1:B

小题1:A

小题1:D

小题1:根据While sweeping leaves on the ground, my five-year-old son Nick came over and asked me to write something on a piece of paper to make a sign for him.可知选C。

小题1:根据下文had collected many stones from all over.他从各处收集了许多石头,可知他喜欢石头,故选D。

小题1:根据After half an hour, nobody passed by. I walked to him and asked him to go back, but he didn’t.及下文if you believe in yourself, you can do anything. "可知选B。

小题1:这篇短文写的是作者五岁的儿子第一次卖石头的故事,故选A最为恰当。

小题1:if you believe in yourself, you can do anything. "这是一句很有哲理性的话,出自一个五岁的孩子之口,作者很可能被感动,故选D。

实验题

硫代硫酸钠(Na2S2O3)可由亚硫酸钠和硫粉通过化合反应制得。已知:Na2S2O3在酸性溶液中不能稳定存在。

(1)某研究小组设计的制备Na2S2O3·5H2O的装置和部分操作步骤如下。

Ⅰ.打开K1关闭K2,向圆底烧瓶中加入足量浓硫酸,加热。

Ⅱ.C中混合液被气流搅动,反应一段时间后,硫粉的量逐渐减少,当C中溶液的pH 接近7时,打开K2,关闭K1即停止C中的反应,停止加热。

Ⅲ.过滤C中的混合液。

Ⅳ.将滤液经过              、过滤、洗涤、烘干,得到产品Na2S2O3·5H2O。

①Ⅱ中,“当C中溶液的pH接近7时即停止C中的反应”的原因是                             (用离子方程式表示)。

②Ⅳ中,操作步骤是                      

③装置B中盛放的试剂是(填化学式)           溶液。

④有一小组在实验中发现,二氧化硫气体产生缓慢以致后续现象不明显,但又不存在气密性问题,请你推测可能的原因                                                                                                                                               

(2)常用Na2S2O3溶液测定废水中Ba2的浓度,步骤如下:取废水25.00 mL,控制适当的酸度加入足量 K2Cr2O7溶液,得BaCrO4沉淀;过滤、洗涤后,用适量稀盐酸溶解,此时CrO42-全部转化为Cr2O72-;再加过KI溶液,充分反应后得混合溶液V mL,将其平均分成4等份,加入淀粉溶液作指示剂,用0.001 0 mol·L-1的Na2S2O3溶液进行滴定,反应完全时,相关数据记录如下表所示:

编号1234
消耗Na2S2O3标准    
溶液的体积/mL18.0217.9818.0020.03
 

部分反应离子方程式为:

①Cr2O72-+6I+14H=2Cr3+3I2+7H2O;

②I2+2S2O32-=2I+S4O62-

则判断达到滴定终点的现象是                                                                                                                                               ,废水中Ba2的物质的量浓度                                                     _。

单项选择题