It expels gas to descend, and expels water from trim bladders to rise.

它通过排出气体来下降，并通过把水排出气囊来上升。

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Planes must zigzag from one ground beacon to the next, and ascend and descend in steps at each stage obtaining permission from the ground.

飞机从一个地面信标到下一个信标曲折飞行，在每一阶段都要经过地面的许可才能上升和下降。

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Even the weight of the skyscrapers contributes to the progressive engulfing of Bangkok. The soils descend from 1.5 to 5.3 cm each year, and a big part of the megalopolis is already under sea level.

曼谷渐渐被越来越多的摩天大楼吞噬，其地平面每年平均下降1.5到5.3厘米，而曼谷这个大都市的许多部分已经低于海平面。

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The Under-20 World Cup draws only a fraction of the fans that the full World Cup will bring to South Africa, when hordes of supporters from 32 nations will descend on the southern end of the continent.

VOA: standard.2009.10.12

And he tells him to descend from the mountain.

然后让他下了山。

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The Pope used a lift to descend from the plane, and a trolley to move along a red carpet laid out for him.

BBC: Spanish youth welcome Pope

Carmelo Anthony was expected to descend from the mountains of Colorado and restore greatness back to the proud franchise.

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You may not know in real time when the stock will start to descend from its lofty heights but neither does anyone else.

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