单项选择题
A.大豆 B.鱼 C.乳 D.鸡蛋 E.肉
A.6% B.10% C.16% D.20% E.26%
A.尿氮加粪氮与排出氮相等 B.摄入氮与排出氮相等 C.摄入氮大于排出氮 D.摄入氮小于排出氮 E.摄入氮小于代谢氮