a device that people who have difficulty walking can sit on to go up and down stairs in a house

He needs an electric stairlift and can't walk far. 他需要一个楼梯升降椅，而且也走不了太远的路。

The family could not have a stairlift because their stairs were too narrow. 这家人没有办法安装楼梯升降椅，因为他们的楼梯太窄了。