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

$\text{⇒ Answer:}$

$\text{(56). from.}$

$\text{(57). between.}$

$\text{(58). fly.}$

$\text{(59). have.}$

$\text{(60). in.}$

$\text{(61). are.}$

$\text{(62). that.}$

$\text{(63). This.}$

$\text{(64). from.}$

$\text{(65). people. (Cái này mình ko chắc lắm).}$