在数据20，10，40，30，80，90，50中，极差是______．
这组数据的最大数为90，最小数为10，
故极差=90-10=80．
故答案为：80．
— I left my handbag on the train, but luckily someone gave it to a railway official.
— How unbelievable to get it back! I mean, someone _____ it. [ ]
A. will have stolen
B. might have stolen
C. should have stolen
D. must have stolen
目前市场上出售的台式PC机中，Pentium4微处理器的主频一般在______。
A．0.5GHz左右
B．1GHz左右
C．3GHz左右
D．5GHz以上
