OK, so w, first of all, work is being done to the system on the left hand side here.

好的，首先,我们通过左边对系统做功。

youdao

Happiness lies, first of all, in health. G. W. Curis, American writer.

幸福首先在于健康。——美国作家寇第斯。G.W。

youdao

Happiness lies, first of all, in health. G. W. Curis, American writer.

幸福首先在于健康。——美国作家寇第斯。G.W。

youdao