赞题库-背景图
单项选择题

From the passage we may infer that the smallest delivery unit in the postal system in U. S.A. is a ______.

A．a state.
B．delivery station.
C．a geographical area.
D．metropolitan post office.
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热门试题

单项选择题The Zip Code, the numerical system, was publicized in ______.

A．1943.
B．1963.
C．1974.
D．not know.

单项选择题The Zip Code system is used so as to ______.

A．read addresses quickly.
B．handle mail by machines.
C．sort out mail very fast.
D．do all of the above.