A:where
B:that
C:which
D:who
pH
3.5~4.5
2.9~3.3
6.3~6.6
7.6~8.0
食物
A.葡萄汁
B.苹果汁
C.牛奶
D.鸡蛋清
直线y=kx+1与圆x2+y2-2y=0的位置关系是 ( )