屈肘动作的完成是由于( )
A:肱二头肌收缩
B:肱三头肌舒张
C:肱二头肌收缩的同时肱三头肌舒张
D:肱二头肌等屈肌肌群收缩,同时肱三头肌等伸肌肌群舒张
乘车人数情况统计图
________that she is interested in children,I am sure teaching is the right job for her.
在KClO3分解制O2的反应中MnO2作催化剂,下列有关催化剂说法不正确的是( )