圆周率用字母π表示,π=3.14.______.
圆周率是圆的周长除以直径的商,用字母π表示,计算时通常取3.14;
所以本题π=3.14说法错误;
故答案为:错误.
There is no doubt ________ China has made a great breakthrough in developing education in the
countryside.[ ]
A. /
B. which
C. that
D. what
完全相关关系即为()关系,其相关系数r=()。