与血β2-M水平有关的是()
A.体重
B.年龄
C.炎症
D.肿瘤
E.性别
参考答案:C, D
He is _____ honest man and now he is living in Belgium, _____ European country.
A.an; an
B.a; an
C.an; a
D.an; the
ESI电喷雾离子化