A:近圆性
B:共面性
C:同向性
D:周期性
B
From — To
Ways
Cost
Time
Comfortable
Popular
Xizhimen — Beijing Railway Station
Bus
¥1
40 minutes
*
**
Taxi
¥20
10 minutes
***
Subway
¥3
30 minutes
Bike
/
1 hour
London— Paris
Coach
(长途汽车)
£30
7 hours
Plane
£100
1 hour and
15 minutes
Train
£60
3 hours
Ferry
(渡轮)
£45
6 hours
Shanghai — Tianjin
¥280
15 hours
¥1000
2 hours
¥180
20 hours
¥286
14 hours
— Sorry, I _______ it.
已知二次函数y=ax2+bx+c(a≠0)的图象如图,给出以下结论,其中正确的结论的个数是( )①abc<2;②当x=1时,函数有最大值;③当x=-1或x=3时,函数y的值都等于0;④4a+2b+c<0.
某校为了解本校学生每周阅读课外书籍的时间,对本校全体学生进行了调查,并绘制如图所示的频率分布直方图(不完整),则图中m的值是____ .