They direct the transmission of power most of the time, but are not the major source of it.

四肢的肌肉大部分时间是指导动力的传输，但是不是动力的主要来源。

youdao

They direct the transmission of power most of the time, but are not the major source of it.

四肢的肌肉大部分时间是指导动力的传输，但是不是动力的主要来源。

youdao