蛋白质净利用率表达为()
A.消化率X生物价
B.功效比值X生物价
C.消化率X功效比值
D.利用率X生物价
E.消化率X利用率
参考答案:A
To have a dinner at a restaurant on the Eve of the Spring Festival, you need to reserve the restaurant
months before it, ____? [ ]
A. mustn't you
B. didn't you
C. don't you
D. needn't you
地月系的共同质心位于()。
A、地球质心
B、地球内部、非地球质心的一点
C、地月之间的空间某处
D、月球质心