下列选项中，（）不是根治计算机病毒的原则。
A.加强教育和宣传
B.采取更有效的措施
C.建立健全法律和管理制度
D.不必要安装和升级杀毒软件
参考答案：D
阅读短文，然后判断正(T)误(F)。
I have two friends. This is Jenny. She is a girl. She lives in Canada. She is eight. She is my friend. And
this is Li Ming. He is a boy. He is nine. He lives in China. He is my friend, too.
( ) 1. I have 5 friends.
( ) 2. Jenny is 8.
( ) 3. Li Ming is a boy.
( ) 4. Jenny lives in China.
( ) 5. Li Ming is 7.
( ) 6. Li Ming lives in Canada.
蒸汽湿度的测定方法很多，以下选项中不属于该测定方法的是( )。
A．热平衡法 B．氯根法 C．氟根法 D．碱度法
