Jerry needs the airport before 9:00 am.
A:get to
B:got to
C:getting to
D:to get to
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将物体以60J的初动能竖直向上抛出,当它上升至最高点时,机械能损失10J,若空气阻力大小不变,那么物体落回抛出点的动能为( )