题目

David received a parrot for his birthday. The parrot had a poor vocabulary, and many were not polite. David tried hard    26    the bird’s words and was often saying polite words, playing soft music, trying anything he could think of to set a good example. But nothing ___27   . He shouted at the bird and the bird just got angry and became even __28   . Finally，without any hope，David put it in the freezer. For a few moments he heard the bird kick and cry loudly in it. Then suddenly it was    29    ----- not a sound for half a minute. David was ___30    that he 下列使用酒精灯的操作中，正确的是（　　）A．添加酒精不超过酒精灯容积的13B．用燃着的酒精灯去点燃另一只酒精灯C．用火柴点燃，用灯帽盖灭D．用焰心部位给物质加热