广告代理制
参考答案：是指在广告经营活动中，广告主委托广告公司进行广告策划和实施，广告媒介通过广告公司承揽广告业务，广告公司处于核心地位的经营体制。
.Professor White has received a letter ___ to give a lecture in Peking University.
A．to be invited
B．being invited
C．invited
D．inviting him
绝经前后诸证
