【单选题】具有“剑脊”和背鳞行数成双性状特征的药材是
【多选题】下列说法正确的有:( )
A.
物体具有向东的速度,却可能具有向西的加速度。
D.
作圆周运动的质点其速度和加速度方向一定垂直。
【单选题】下列说法中,正确的是 ( )
D.
一物体具有沿x轴正方向的加速度,其速度有可能沿x轴的负方向
【简答题】第三节 完形填空(每小题1分) 阅读下面短文,从短文后各题所给的四个选项中,选出可以填入空白处的最佳选项。 Scientists find that hard-working people live longer than average men and women. Career women are 1 than housewives. Evidence (证据) shows that 2...
【单选题】下列说法中,正确的是
A.
一物体具有沿 x 轴正方向的加速度,其速度有可能沿 x 轴的负方向
【简答题】People go to work in different ways ( 以不同方式 ). It depends on ( 依赖于 ) where they are. Some people walk to work because they live near their workplaces. Some people go to work by bike because they live ...