There was once a lonely girl who wanted love very much．One day while she was walking in the forest，she found two birds．She took them home and put them in a small1．She was happy to have two“friends”．She2them with love and the birds grew strong．One day the girl forgot to close the door of the cage．The 3of the two flew out of the cage．The girl was afraid that it would fly away．She caught it quickly．She felt glad that she caught the bird before it could fly away．Suddenly she couldn’t4a sound from the bird．When she opened her hand，the bird was already（已经）dead．Her5killed(杀死)the bird! Then she saw6bird jumping up and down7the cage．She could feel its great need for freedom．It wanted to fly into the blue sky．So she let it fly away8．The bird circled(转圈)once，twice，and three times．The girl9as the bird flew．She didn’t care about losing the bird any more．She wanted it to be happy．Suddenly the bird flew closer and landed softly on her shoulder．It sang the10song she had ever heard(她所听过的)．
The fastest way to lose love is to hold it too tightly，and the best way to keep love is to give it wings．

实验名称：卤素单质的氧化性强弱比较

实验药品：KBr溶液、KI溶液、氯水、溴水、碘水、四氯化碳、淀粉碘化钾试纸

请回答：

4.7272…是（　　）小数．