translation.en: I worked a long time on figuring out how to move the arms over a much greater arc -- that is up and down -- and make them a lot easier, so that you didn't have to use a button.
translation.zh: 我工作了很长时间才明白 如何把扶手椅移动成一个很大的角度， 这样上下移动， 让它们更容易移动 所以不需要去按一个按钮。