A:km
B:m
C:mm
D:cm
下面的临界值表供参考:
P(K2≥k)
0.15
0.10
0.05
0.025
0.010
0.005
0.001
k
2.072
2.706
3.841
5.024
6.635
7.879
10.828
独立性检验统计量 K2=n(ad−bc)2(a+b)(c+d)(a+c)(b+d), 其中 n=a+b+c+d.
My uncle is a farmer. He has ninety 1trees on his farm. My uncle and my2can't pick(采摘) all the apples in fall(秋天).3 they ask my parents and me to 4 them every year. It's Sunday. My parents don't go to5and I don't go to school. So we'll go to the6. We get up early(早) in the 7 My mother is in 8 old clothes. My father buys many kinds of food for my uncle's 9in a shop. She likes them very much. My uncle and aunt 10 us many apples, too. I like to work on the farm.