Colombo is one of the port cities of ______.
A.Sir Lanka
B.India
C.Malaysia
D.Iran
参考答案:A
已知a2+b2=c2,其中a=5,b=12,求c的值.
已知一组数据:15,13,15,16,17,16,14,15,则这组数据的极差与众数分别是( )
A.4,15
B.3,15
C.4,16
D.3,16