The newspaper will have to close down if it cannot increase its ________ considerably.
D
circulation：(书报杂志的)销售量，发行额，销路。符合句意。
翻译：WewishtocallyourattentiontothevalidityoftheL/C,sincethereisnopossibilityofL/Cextension.
Willyousendus_____returnmailpamphletsandpricelist____yourexports?
Canyouofferusmachinetools___thefollowingspecification?
As activity carried ________ as one thinks fit in one’s spare time, leisure has several functions.
ltisnecessary___youtocomplywithourshippinginstructions.