1- = + = × × =
60×30%= 0÷ = + - - =
1.92÷0.04= 8.3-2.53= 5.7×3.2-2.2×5.7=
直线条数
1
2
3
4
5
交点个数
0
1+2=3
6
7
8
9
10
A.1:1
B.1:π
C.π:1
D.2: 1