A:whe
B:where
C:the
D:which
下列关于惯性说法正确的是( )
We haven't seen her for many days and there is ______ for her safety.
如图所示,请画出茶壶受到的重力G的示意图,若人在倒茶水时,以O为支点,请画出作用在A点上的最小动力F及其力臂l.