[xìng mìng guān tiān]   

性    命    关    天    犹言性命交关。形容关系重大，非常紧要。

指犹言性命交关。形容关系重大，非常紧要。

A case involving human life is to be treated with the utmost care

性烈如火    性急口快    性命交关    性命关天