在推铅球的过程中,上臂肱二头肌和肱三头肌的活动状态分别是( )
A:收缩 舒张
B:舒张 收缩
C:同时舒张
D:同时收缩
—That's too dangerous, so we should pay attention to our safety.
— May I have a look?()
—