A simple pulley is used in a flagpole to hoist a flag , whereas block and tackle machines are used on ships to lift heavy sails .
(A simple pulley; is used; L:in a flagpole; to hoist a flag) (A simple pulley; to hoist; a flag) (block and tackle machines; are used; L:on ships; to lift heavy sails)
A simple pulley A simple pulley block and tackle machines
is used to hoist are used
L:in a flagpole to hoist a flag
a flag
L:on ships to lift heavy sails