The repeated thrust applications at apoapsis would raise periapsis from inside to outside the stationary orbit.

重复在远施以推力，会将由同轨道到同轨道外。

Now thrust could be generated (for “free” again) at periapsis, progressively increasing the altitude of apoapsis.

这时可以「免费」在产生推力，渐渐将远的高度。