Which of the following coverage usually covers partial loss or damage resulting from natural calamities？（）

单项选择题In（）the bunker is payable by the shipowner.

A.voyage chartering
B.bareboat chartering
C.time chartering
D.contract of affreightment

多项选择题A freight forwarder can provide services to（）.

A.retailers
B.importers
C.exporters
D.the overseas importer

多项选择题（）are the barriers to international trade.

A.capital
B.import duties
C.non-tarriffbarrier
D.import quotas

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.

A.the providing of services
B.the utilizing of services
C.the booking of space
D.the loading and unloading

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

A.invalid
B.valid
C.clean
D.dirty