甲、乙两人在相同的条件下,各射靶 10 次,经过计算:甲、乙射击成绩的平均数都是 8 环,甲射击成绩的方差是 1.2,乙射击成绩的方差是 1.8.下列说法中不一定正确的是( )
A:甲、乙射击成绩的众数相同
B:甲射击成绩比乙稳定
C:乙射击成绩的波动比甲较大
D:甲、乙射中的总环数相同
Swimming club
Do you like to swim? Do you want to swim well? Then we have good teachers to teach you. Opening time:2: 00 p.m ~ 9: 30 p.m
Ticket price: 15 yuan for children, 20 yuan for adults(成人)
Please call Mr. Wang at 877-778
Children dancing club
We are a dancing club for children of 5~14. we have lessons from 9:00 to 10: 30 every Saturday and Sunday.
If you like dancing, just join us.
Call Miss Wu at 263-566
两次工业革命在促进了生产力巨大飞跃的同时也加强了人类不同地区之间的联系使世界逐渐连成一个整体。阅读下列图片和材料,回答问题:
图一早期火车机车 图二早期汽车
请回答: