A:0°和90°
B:20°W和160°E
C:90°W和180°
D:20°E和160°E
By no means _____ true that all English people know their own language well.
如图所示,一辆小汽车质量为1.2t,发动机的功率为60kW,停在水平地面上时,四轮与地面的总接触面积为1000cm2.当它在水平公路上以20m/s的速度匀速行驶1440m时,求: