A:0.25A、20Ω
B:1A、20Ω
C:0.4A、10Ω
D:1A、 10Ω
The fact that lets artists down is that Peking Opera, a 200-year-old art form, is losing popularity.
下图中农业地域类型的经营特色与阿根廷的典型农业地域类型一致的是( )
Tony never spends money on buying books he doesn't like reading.
在水平地面上有质量为4kg的物体,物体在水平拉力F作用下由静止开始运动,10s后拉力减为F/3,该物体的速度图象如图所示,则水平拉力F=____N,物体与地面间的动摩擦因数μ=____。(g取10m/s2)