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Rockets 101 | National Geographic
学习统计
CEFR 等级
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- [Narrator] The ground begins to tremble.
- [Announcer] Three.
- [Narrator] Massive engines roar to life.
- [Announcer] Two.
- [Narrator] Billowing clouds of exhaust.
- [Announcer] One.
- [Narrator] And then a blinding pillar of fire.
- [Announcer] Liftoff. We have a liftoff.
- [Narrator] A mighty voyager leaves the Earth behind
to explore the vast universe among the stars.
Launching a rocket into space
is one of humankind's crowning achievements.
Although they come in many different shapes and sizes,
all rockets are propelled by engines that produce thrust.
The rockets that launch into space
are made up of four major systems, based on function.
The structural system makes up the frame
that holds the rocket together
and consists of the cylindrical body, nose cone, and fins.
Next, the propulsion system
takes up the most amount of space
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