139. A substantive in the accusative case may be used, instead of
a prepositional phrase or an adverb, not only to express measure
(duration) of time (91), but also to express measure of weight, price,
length, etc.:
Li marsxis dek unu mejlojn, he walked eleven miles.
La parko estas largxa tri mejlojn, kaj longa kvar mejlojn,
the park is three miles wide and four miles long.
La tablo pezas dek du funtojn,
the table weighs (is heavy) twelve pounds.