一架直升机在茂密丛林中的一片空地着陆了。
她说：“我先是看到一片什么东西从空中飞过，然后我看到那架直升机扎进水中”，她还说公园里的人们几乎都惊呆了，反应不过来。”
"First I saw a piece of something flying through the air. Then I saw the helicopter going down into the water, " she said, adding that the crowd in the park seemed too stunned to react.
而旋翼桨叶片数的选择，对轻型和中型直升机来讲，4片桨叶旋翼和5片桨叶旋翼具有典型意义。
As to the selection of rotor blade number for light and medium helicopter, 4 blade and 5 blade rotor are typical.
而旋翼桨叶片数的选择，对轻型和中型直升机来讲，4片桨叶旋翼和5片桨叶旋翼具有典型意义。
As to the selection of rotor blade number for light and medium helicopter, 4 blade and 5 blade rotor are typical.
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