潜水员必须确保他们的脐带管连接牢固，以防氧气供应中断。

The divers double-checked their ___umbilicals to prevent any disconnection of the oxygen supply.

毕业后，他逐渐剪断了与父母的依赖关系，开始自己谋生。

After graduation, he gradually cut the ___umbilical cord to his parents and started to earn his own living.