题目

Crime is a serious problem in Britain. One sort of crime which particularly worries people is juvenile crime—that is, crimes committed by young people. For some years, juvenile crime has been increasing. There are two main sorts of juvenile crime：stealing and violence. Most people do not understand why young people commit these crimes. There are, I think, a large number of different reasons. These crimes are not usually committed by people who are poor or in need. Young people often dislike and hate the adult world. They will do things to show that they are rebels. Also in Britain today it小明用相同的酒精灯分别给水和煤油加热（如图甲），以探究水和煤油的吸热能力，（1）本实验需要用到天平这一测量工具，目的是________________________________。（2）加热10min，水吸收的热量____________（填“大于”、“小于”或“等于”）煤油吸收的热量。（3）根据实验数据，小明作出了水和煤油的温度随加热时间变化的图象（如图乙），由图象可知，水的沸点是___________℃，煤油的比热容是_________J/（kg•℃），【】（4）若本次实验共消耗酒精20g，则这些酒精完全燃烧发出的热量是___________J。（）