两名同学进行了10次三级蛙跳测试，经计算，他们的平均成绩相同，若要比较这两名同学的成绩哪一位更稳定，通常还需要比较他们成绩的（ ）
A：众数
B：中位数
C：方差
D：以上都不对
①民族复兴的重任完全要靠党员干部来承担
②要认识自己扮演的角色，尽到自己的责任
③对自己负责就一定能承担起对社会的责任
④要具有社会责任感，做一个负责任的公民
月份
1
2
3
4
5
6
7
8
9
10
11
12
气温(℃)
13
16
20
23
22
19
15
降水(毫米)
45
41
49
43
29
27
52
89
71
53
用适当的介词填空
（1）He was born____ a cold morning.
（2）The girl began to learn to play the piano____ an early age.
（3）The beautiful music was____ Gu Jianfen.
（4）We often watch concerts____ TV.
（5）The boy can play all types____ instruments(乐器).
Hello，I'm Fangfang. I'm 10. My favourite letter is A. Yellow is my favourite colour. This is Sam. The ABC song is his favourite song. His favourite colour is blue. D is his favourite letter.
