国产丝袜极品视频在线观看_午夜精品一区二区成人免费_色偷偷亚洲男人天堂岛_亚洲AV自慰白浆喷水肥臀_中文在线理伦视频在线播放

April 15, 2014 at noon, Associate professor Liu Tiezhong from the National Economy Mobilization Education and Training Center gave a presentation on "Community anti-airraid and anti-disaster risk assessment methodology - in example of Haidian District, Beijing" at Room 418 in the main building. He had exchanges and discussion on the topic with the fellow teachers and doctoral students.