— Whose is this?
— It's your ____. [ ]
A. brothers
B. brother's
C. brother
答案:B
SLE患者体内增高的Ig类型有()。
A.IgM
B.IgG
C.IgE
D.IgA
E.以上都不对
求出下列物质中加点元素的化合价:
(1)KN-O3______.
(2)Na2C-O3______.
(3)H2S-O4______.
(4)C-O______.
(5)Ca(C-IO)2______.
(6)N-H3______.
(7)Fe-O______.
(8)Al2(S-O4)3______.
(9)O2-______.