11．听下面一段独白，回答第12至第15四个小题．现在你有20秒钟的时间阅读这四个小题．听完独白后，你有20秒钟的时间来选择有关选项．独白连读两遍．
12．What don't we need to do the experiment？
13．Before placing the coin on the top of the bottle，what should we do？
A．Place them in order．
B．Place them in the warm water．
C．Place them in the cold water．
14．When we hold the bottle for some seconds，what will happen？
A．The coin will jump by itself．
B．The coin will fall off the top of the bottle．
C．The coin is still there．
15．According to the experiment，what can we do if we want the coin to fall？
A．Put the bottle in the warm water．
B．Move your hands away from the bottle．
C．Place the coin on the top of the bottle．
