同一平面内三条直线互不重合,那么交点的个数可能是[ ]
A.0,1,2
B.0,1,3
C.1,2,3
D.0,1,2,3
答案:D
在滚动轴承公差等级标准中,P0级精度最低,为普通级,应用最广。( )
—Are you happy ________ your English study?
—Yes, I think so. [ ]
A. for
B. with
C. in
D. at