阅读下面短文, 从短文后各题所给的四个选项(A、B、C、D)中, 选出可以填入空白处的最佳选项。
    One day,it was raining heavily and I didn't have an umbrella,I had just1a bus and had to walk back to my house.I2walking in that direction,when I heard somebody shouting,“Sister,”“Sister.” I looked back and3the stationery（文具）shopkeeper.I went to him and asked what was the4.He said that since it was raining heavily,I could take a5in his shop,have a look at his new6and go home when the rain stopped.For a moment I hesitated（犹豫）,but the7of getting to have a look at the pens made me nod.
    To my surprise,I found that the8was larger than I thought.The stationery shopkeeper offered me a chair and took out the pens for me.I9a beautiful parker（派克）pen and had a try.It10so smoothly that I wanted to buy it with all my heart,11as expected,it was very expensive.The shopkeeper said,“I can give you the pen for ninety-five dollars12one hundred.”I looked up and thanked him for the13,but refused politely as it was14quite expensive for me.By that time,the rain had15,and after appreciating his16,I quickly walked back to my house.
    After that day,the shop became my17place to hang out .The shopkeeper used to18me pens always at discount prices and very often also offered me tea.He had much information about all kinds of pens and other writing instruments.19both of us knew nothing about each other,we had a deep friendship based on our common 20.

塑化剂是工业上被广泛使用的高分子材料助剂，在塑料加工中添加这种物质，可以使其柔韧性增强，容易加工．塑化剂可合法用于工业生产，但禁止作为食品添加剂．截止2011年6月8日，台湾被检测出含塑化剂食品已达961种，据媒体报道，2012年岁末，我国大陆多种著名品牌白酒也陷入了塑化剂风波．常见塑化剂为邻苯二甲酸酯类物质，某有机物J（C₁₉H₂₀O₄）是一种塑料工业中常用的塑化剂，可用下列合成路线合成．

已知：Ⅰ．

Ⅱ．控制反应条件，使物质A中的支链Y不与NaOH溶液发生反应；

Ⅲ．F与浓溴水混合不产生白色沉淀．

请回答下列问题：

下列不属于共生现象的是（  ）

阅读下列材料，回答问题。

材料一 中关村是中国体制机制创新的试验田，是科技创新的代名词，这里有联想，京东，百度等一批领军企业；有日益完善的科技服务体系，包括27家创新型孵化器，110多家社会组织；有“勇于创新，不惧风险，旨在领先”的精神和“鼓励创业，宽容失败”的风气，无数有梦想的人聚集在中关村的旗帜下。这个号称“中国硅谷”的地方，通过改革释放出创新创业的活力。

材料二 2015年是我国人民大表大会成立61周年。实践充分证明，人民代表大会制度是符合中国国情，体现我国社会主义国家性质，保证人民当家作主的根本政治制度，也是党在国家政权组织中贯彻群众路线，充分发扬民主的最好实现形式。党的十八大提出，要增强道路自信，理论自信，制度自信。在制度上的自信之一就是坚持人民代表制度不动摇。人民大表大会制度的建立，为中国社会主义制度的建立和发展打下了政治基础，极大的调动了全国各族人民建设国家、管理国家的积极性。

材料三 某小区因为广场舞发生了纠纷。住户觉得，楼下的广场舞音乐声音大，影响休息，就往下泼水、扔脏物，跳舞的居民觉得广场舞愉悦身心、强身健体，在公共广场跳舞是自己的权利。一方想跳舞健身，另一方想享受安静，当合理需求遇上正当权益，广场舞何去何从？

某钢铁厂用100t含氧化铁80%的赤铁矿炼铁，计算理论上可冶炼出铁的质量．