53. (I) Ancient seafarers found their way by observing
landmarks, such as large rocks or trees, along rivers
and coastlines. (II) When out of sight of land, they
derived clues about their location by measuring water
depth, monitoring wind patterns and wave shapes,
and observing the positions of the Sun and the stars.
(III) Later, navigators developed tools to measure a
ship’s position and progress more precisely.
(IV) They can choose from a great variety of high-
tech tools to determine their position on Earth and
find their way from one place to another. (V) They
used a magnetic compass to determine direction,
measured the height of the Sun or stars on the
horizon to fix their position, and plotted their progress
and routes on nautical maps called “charts”.
A) I B) II C) III D) IV E) V