lifeline

The river is the town's lifeline.这条河是小镇的命脉。

The new jobs were an economic lifeline for a city in need of help.对于一个需要帮助的城市而言，新的工作岗位是其经济的生命线。

The radio was their lifeline to the outside world.那台收音机是他们与外界连接的生命线。

They threw a lifeline to the man overboard.他们把救生索扔给那个从船上落水的人。