申请或取得三级保密资格的单位可以成立保密委员会。（）
参考答案：对
All the students in this school are required to________at least two lectures on how to study every month.[ ]
A. attend
B. take part in
C. join in
D. go in for
去甲肾上腺素释放后，主要代谢消失方式是
A．被肾排泄B．被MAO代谢C．被COMT代谢D．被突触前膜重摄取入囊泡E．被胆碱酯酶代谢
