反应N2(g)十3H2(g)=2NH3(g)当用-dCN2/dt表示其反立速率时,与此速率相当的表示是()
A.A
B.B
C.C
D.D
E.E
参考答案:B
— What colour is Canada's flag? — It's . [ ]
A. red and yellow
B. red and white
C. red, white and blue
昼夜分阴阳,则上午为()
A.阴中之阳
B.阳中之阳
C.阳中之阴
D.阴中之阴
E.阴中之至阴