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 （）.

单项选择题 The services that a freight forwarder renders may often range from routine and basic tasks such as（）or customs clearance to a comprehensive package of services.