读一读，写一写。

阅读下面短文，然后根据括号内所给汉语意思写出单词的正确形式（每空一词）。

    Last weekend I went to visit my grandma. ____ (虽然) her house is far from mine, I still decided to walk there. It was very sunny so I didn't take my ____ (雨伞). However, on the way it began to rain hard. And soon I was all ____(湿的). When I was thinking about what to do next,  ____ (幸运地), there came a taxi. I ____ (停) it and went into it quickly. When I arrived at my grandma's house, she was very surprised to see me.

     "Is it ____ (必要的) for you to come here on foot?  Why didn't you drive your car here?" She asked.

   "Because I want to take more exercise." I answered.

     "Why did you come on ____ (这样的) a rainy day?"

     "I came to tell you a piece of good news."

   "What good news?"

     "I  ____(赢) the first prize in the singing ____ (比赛)."

     "Congratulations!" said my grandma excitedly, then she ____ (给) me a warm blanket to wrap me.

完善产权保护制度是坚持社会主义基本经济制度的必然要求，是推动经济持续健康发展的迫切需要。健全以公平为核心原则的产权保护制度，毫不动摇地巩固和发展公有制经济，毫不动摇地鼓励、支持、引导非公有制经济发展，公有制经济财产权不可侵犯，非公有制经济财产权同样不可侵犯。

结合材料，运用我国基本经济制度的知识，分析“平等保护各种所有制经济财产权”的正确性。

一段平直钢管长1.02km，大明站在该钢管的一端，大亮站在该钢管的另一端  ，大明用锤子敲击一下钢管，大亮先后听到了两次响声  。已知声音在空气中的传播速度为340m/s，在钢管中的传播速度为5100m/s，求：大亮听到两次响声的时间间隔为多少s？