a precarious future/situation/position/existence 变化多端的未来/局面/处境/生活
For the refugees life was always precarious. 对于难民们来说，生活总是朝不保夕。
Her position on the ledge was somewhat precarious. 她处在边缘的那个位置有点岌岌可危。
a precarious chimney 摇摇欲坠的烟囱