Private warehouses are operated by the carriers. ( )

Modulation is the process of loading low-frequency signals onto high-frequency carriers. ( )

What does the author mean by "Aviation has been incompletely deregulated .... "(Para. 3) A: Governmental restrictions are still imposed on aviation industry in many areas. B: Governments help establish rules for aviation industry only in America and Europe. C: Some countries hope to help their national carriers keep up their national prestige. D: Many countries discourage merger plans between foreign and domestic carriers.

what kind of products do the air carriers deliver? （）

Door-to-door services refer to carriers（）goods in the shippers＇and consignees＇ warehouse.

The International Air Transport Association was established in Cuba in 1945 and it’s an association of airlines and subsidiary carriers.

中国大学MOOC: 4. By focusing on last-mile delivery alternatives retailers are able to compete with giant shipping carriers.

The law is expected to improve the efficacy of surveillance on HIV carriers. A: inspection B: investigation C: observation D: restriction

Because semiconductor has two kinds of carriers, it has better conductivity than conductor

The carriers which can be used for paper-cutting are ( ) A: silk B: leather C: paper D: leaf