性 ㄒㄧㄥ ˋ xìng 命 ㄇㄧㄥ ˋ mìng 攸 ㄧㄡ yōu 关 ㄍㄨㄢ guān 性 ㄒㄧㄥ ˋ xìng 命 ㄇㄧㄥ ˋ mìng 攸 ㄧㄡ yōu 關 ㄍㄨㄢ guān vitally important a matter of life and death