同一批资料对回归系数β和相关系数r作假设检验，其结论是（）。
A.是相同的
B.是不同的
C.不一定相同
D.肯定不同
E.r为负β为正
参考答案：A
海洋的深处没有绿色植物的生存是因为那儿温度太低．______．
读句子，选答语。
( )1. What's the weather like today?
( ) 2. Is this your dog?
( )3. How many cows do you have?
( )4. How much is the coat?
( )5. Are they horses?
A. I have two.
B. Yes, they are.
C. No, it isn't.
D. It's sunny today.
E. It's ninety yuan.
