HELICOPTERS
Helicopters have one distinct difference (56)______________ all other vehicles, it is
that they can fly vertically. Helicopters can fly (57)______________ jungles and forests,
hills and mountains, and they can take off or (58)______________ almost everywhere.
Because of this, they (59)______________ been especially useful for explorers.
In the jungles of South America, helicopters have helped explorers (60)______________
looking for new places to drill oil wells. They (61)______________ used to bring in very
heavy drilling equipment and anything (62)______________ may be needed.
Big helicopters can lift loads up to ten tons. They can go anywhere and hover over a
chosen spot. (63)______________ makes helicopters excellent flying cranes. Helicopters
have rescued people (64)______________ the seas and mountains. As they get more
efficient, they will be used by many (65)______________ a regular basis.
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