If I ____ a bird, I would fly in the sky. [ ]
A. were
B. am
C. was
D. be
答案:A
能在溶液中大量共存的一组离子是( )
A.Cu2+、SO42-、OH-、K
B.Na、CO32-、H+、Cl-
C.H+、Cl-、NO3-、Ba2+
D.Ca2+、H+、CO32-、NO3-
胆固醇在体内代谢的主要去路是()
A.转变成维生素D3
B.转变成性激素
C.转变成类固醇激素
D.转变成胆汁酸
E.转变成胆红素