A:2.5 mol
B:4.5 mol
C:5mol
D:7.5 mol
用显微镜观察玻片标本的时候,向左、向上移动玻片标本时,图像的移动方向是( )
When a driver sees the sign "STOP", he ______ stop. He ______ go on.
习惯上划分东西半球的分界线是( )