血红素合成的原料是
A.乙酰CoA、Fe2+B.珠蛋白、Fe2+C.乙酰CoA、甘氨酸、Fe2+D.琥珀酰CoA、Fe2+E.琥珀酰CoA、甘氨酸、Fe2+
参考答案:E
________from space, the earth, with water_____seventy percent of its percentage, looks like a “blue ball.”
A.Seen; covered
B.Seeing; covering
C.Seeing; covered
D.Seen; covering
轻型飞机的金属桨叶轨迹检查要求6英尺直径处,其轨迹偏差在()之内.