用手捏心脏,壁最厚的腔是( )
A:左心室
B:右心室
C:左心房
D:右心房
Could you please pay ____ ____?
Name
Favorite sport
How often
Favorite player
Dream
Jack
football
often
Ronaldo
scientist
Steve
swimming
twice a week
Sun Yang
great swimmer
Marry
tennis
every day
Li Na
dancer
如图所示,粗糙水平圆盘上,质量相等的A、B两物块叠放在一起,随圆盘一起做匀速圆周运动,设物体间最大静摩擦力与滑动摩擦力相等,则是下列说法正确的是( )