A:mustn’t leave
B:shouldn’t have left
C:couldn’t have left
D:needn’t leave
— Are you a fan of Zhou Libo?—Yes. Not only I but also my sister him very much.
如图,△ABC三个顶点的坐标分别为A(2,2),B(4,2),C(6,4),以原点O为位似中心,将△ABC缩小为原来的一半,则线段AC的中点P变换后在第一象限对应点的坐标为____ .
唐朝的读书人为了实现“朝为田舍郎,暮登天子堂”的理想,最佳途径应该是( )