translation.en: But then I knew from experience and looking around in offices where there were chairs with headrests that nobody would ever bother to reach back and turn a knob and adjust the headrest to put it in position.
translation.zh: 但是当我从经验中得知， 并对办公室中 有头靠的办公椅进行了调查后发现 没人愿意把手 伸到背后去拧一个把手 来调节头靠的位置。