举腿：在椅子上坐直，脚放在地板上，然后把膝盖弯曲尽力向胸靠拢。

Lifts: Seated in a chair with your back straight and your feet on the floor, squeeze knees together and gently bring them toward your chest.

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如果你想让飞行员知道降落是安全的，把你的手伸到前面并弯曲你的膝盖。

If you want the pilot to know that it's safe to land, push your hands out in front of you and bend your knees.

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把上半身和腿同时抬起，但不要弯曲膝盖。

Simultaneously raise legs and torso. Don't bend your knees!

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