n.命脉；生机的根源
Trade is the lifeblood of our country. 贸易是我国的命脉。
Tourism is the area's lifeblood. 旅游业是这一地区的命脉。
Teachers are the lifeblood of a school. 老师是学校的灵魂！
The girl is the lifeblood of her mother. 这女孩子是她母亲的命根子。
