《中华人民共和国无线电管理条例》第二十三条规定，任何单位和个人未经国家无线电管理机构或者地方无线电管理机构批准，不得转让频率。
参考答案：对
A．NH3·H2O
B．BaCl2
C．NaOH
D．HCl
12. The teacher didn't _____ to my questions which were not too difficult for me to think over.
A．answer
B．tell
C．say
D．Reply
