颅面部生长发育的研究方法包括
A．人体测量
B．放射性同位素
C．种植体
D．X线头影测量
E．组织切片
参考答案：A,B,C,D,E
My brother usually _____ his room after school. But now he _____ soccer. [ ]
A.cleans; plays
B.cleaning; playing
C.cleans; is playing
D.cleans; is playing the
在某无色酸性溶液中能大量共存的一组离子是（ ）
A．Na+、K+、HCO3-、NO3-
B．NH4+、SO42-、Al3+、NO3-
C．Na+、Ca2+、NO3-、CO32-
D．K+、MnO4-、NH4+、NO3-
