血红素合成调节的限速酶是
A．ALA合酶B．ALA脱水酶C．亚铁螯合酶D．HMGCoA合成酶
参考答案：A
— I'm terribly sorry that I made your table cloth dirty.
— _____. [ ]
A. Never mind
B. Don't mention it
C. That's right
D. Sorry
超滤是以（）作为推动力。
