“hang by a thread”别理解成“用一个绳挂起来”，真实含义是千钧一发，岌岌可危，危在旦夕。

【例句】
After the loss, their chances of getting into the championships are hanging on by a thread.
输掉比赛后，他们进入锦标赛的机会岌岌可危。

Her life hung by a thread as medics rushed her to the hospital.
当医护人员将她送往医院时，她的生命危在旦夕。