题目

阅读下面短文，然后从各愿所给的四个选项中选出一个最佳答案。Hi, boys and girls1toour school. Here's a picture2school.It is a beautiful middle school. You can see three buildings (大楼). There are sixty3inthe buildings. And each(每间) classroom has 30 orangedesks4chairs.Look at that green building! It's5schoollibrary. It's very big and6.You can7lotsof books in it. They are in the bookcases. All the teachers are very8. They are our good friends. And we9ask them for help. I10you will have good days here. （1） A . Welcome B . Watch C . Look 已知甲、乙两组数据的平均数分别是.x甲=80，.x乙=90，方差分别是S甲2=10，S乙2=5，比较这两组数据，下列说法正确的是（　　）A．甲组数据较好B．乙组数据较好C．甲组数据的极差较大D．乙组数据的波动较小