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

重远心点施推力，会将近心点由同轨道内提升到同轨道外。

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

这时可「」近心点产生推力，渐渐将远心点的高度提升。