Have you ever had the experience of drinking water that was

Have you ever had the experience of drinking water that was just boiled(煮沸的)? It hurts you because it's too hot. But if you wait too Iong, the water may get cold.    
     Can you find a bottle that you can drink water comfortably but can'l be hurt by the hot water.  
Scientists found drinking 40-degree water is best for our health. Now a girl has found the bottlc. She is a
middle school student named Xiang Zeyu. She  is  from Xi'an, Shaanxi.  She is studying at Xi'an Aizhi
Midclle School.  The 15-year- old girl came up with the idea when she heard her younger sister complain
that her boiled water was toohot or too cold to drink. She decided to make all inveIltion that could tell the proper time to drink the boilecl watu. Xizing and her classmate Li Jingyi first bought a tem lierature
detector(检测器)that had been set to sense the temperature at 40 degrees.  Then they connected(连接)it
to a music chip,a switch(开关)ancl a can with electric wires(电线)．After they cov- ered the can with a
bigger bottle, their invention was ready.  Powered by two AAA batteries(电池),the bottle works well. "
Pour the boiled water into the bottle and turn on the switch, then wait. The bottle will begin to sing when
the temperature is right 40 degrees," Xiang said. rro invent this bottle, Xiang and her classmate spent ~50
and one whole week of their spare ...