多项选择题 Customs clearance in the import-export trade is one of the traditional functions of a freight forwarder.Customs clearance measures mainly include （）。

单项选择题 On traffic lanes where demand is strong and plane capacity is limited， the air rates will be （）and vice versa for traffic lanes where supply exceeds demand.

单项选择题 When one of the original bills of lading being surrendered to the carrier， the others become （）.