下列说法正确的是 A．若|r|＞r0.01(n-2)，变量X，Y间一定有直线关系 B
题型：单项选择题
问题：
下列说法正确的是
A．若|r|＞r0.01(n-2)，变量X，Y间一定有直线关系
B．若|r|＞r0.01(n-2)，则变量X，Y间有正相关关系
C．若X，Y间有相关关系，则说明X， Y间一定有因果关系
D．用最小二乘法确定直线回归方程的原则是各观察点与直线的垂直距离的平方和最小
E．回归系数的假设检验可以用t检验和 F检验，也可以用r的检验代替
题型：单项选择题
The class teacher thought that hobbies were important for children. So she encouraged all her students to have one, and sometimes she arranged hobby shows for their parents to see as a result.
One morning the teacher told the class to have a holiday and get their hobby things to school before 5p.m. A hobby show would be held the following afternoon.
So in the afternoon, the students with nothing to show did their lessons at school as usual, while the lucky ones had a holiday to go home for their hobby works.
When the afternoon lessons began, the teacher was surprised to see that Tommy was not there. “I don’t believe Tommy has a hobby,” she thought. However, at a quarter to five, Tommy arrived with a beautiful collection of butterflies in glass cases. The teacher liked the samples(标本) very much and put them on a desk in the classroom. But, to her surprise, Tommy picked them up again and began to leave.
“What are you doing, Tommy?” she asked. “Those things must stay here until tomorrow afternoon. That’s when the parents are coming to see them.”
“I know that,” answered Tommy, “and I will bring them back tomorrow, but my big brother doesn’t want them to be out of our house at night.”
“But, aren’t the butterflies yours?” asked the teacher.
“No,” answered Tommy. “They are my brother’s”
“But Tommy, you should show your own hobby here, not somebody else’s”
“I know that,” answered Tommy. What surprised her most was the answer, “My hobby is watching my brother collecting butterflies.”
小题1:What did the class teacher think of hobbies for children?
A．Unwelcome
B．Hopeless
C．Harmful
D．Important小题2:What time did Tommy get back to school that afternoon?
小题3:What would NOT happen the following afternoon?
A．The parents would enjoy the show in the classroom
B．Tommy would bring the butterflies back
C．The teacher would encourage her students for hobbies
D．The butterflies would fly away小题4:Which was the teacher’s greatest surprise?
A．Tommy was not at school as usual
B．Tommy picked the butterflies up again and began to leave
C．Tommy said his hobby was watching his brother collecting butterflies
D．Tommy came back to school before 5 that afternoon小题5:What’s the best title for this passage?
A．Important Hobbies
B．Tommy’s Hobby
C．Different Hobbies
D．Collecting Butterflies