如图,质量为m的物体A与水平面间的滑动摩擦因数为μ,受到一与水平方向夹角为的恒力F作用,物体的水平加速度为()
Iwouldverymuch______tovisitsomeoftheplacesthatIhavebeenreadingabout.
Weallknowaboutthe_____thatsmokingcandotoourhealth.
Inmyopinion,theyshoulddosomethingtorewardtheirmost_(produce)employees
两列机械波I、II在传播过程中遇到一障碍物,I的波长与障碍物尺寸相当,II的波长远小于障碍物尺寸,则机械波()