夜间四处飞翔的普通蝙蝠在空中异常灵巧敏捷，但却无法从水平面上起飞。
The ordinary bat that flies around at night, a remarkable nimble creature in the air, cannot take off from a level place.
当然，可由此从行星地球的天空中辨认太阳的运行轨迹，黄道平面在北半球夏季七月的天空中的位置很低。
Of course, defined by the path of the Sun through planet Earth's sky, the ecliptic plane rides low during July nights in the northern hemisphere's summer skies.
如果我们将太阳在天空中的一年内运转轨迹描出，这将是另一个循环，这平面就是整个太阳系的黄道。
If we plot the position of the sun around the sky in a year, it will mark out a different circle in the sky which is the plane of the ecliptic of the solar system.
因为月球和明亮的行星出现在天空中黄道平面附近，这种掩星事件也很平常，但是它们也很富有戏剧性，特别是在望远镜影像里。
Because the Moon and bright planets wander through the sky near the ecliptic plane, such occultation events are not uncommon, but they are dramatic, especially in telescopic views.
研究弯曲时空中平面运动刚体的动力学协变方程。
The covariant equation of plane motion body in curved space-time is studied.
舞者要阻止从空中掉落的惟一方法便是中止自己的动量，而这需要一个反面的来自一个平面的阻力。
The only way a dancer can stop dropping through the air is by stopping the body's momentum, which requires an opposing force-the ground.
本文的另一部分研究了声目标的定位技术，分为平面目标定位和空中目标定位两种。
The other part of the thesis discusses the target location problem which includes targets on the ground and in the sky.
本文的另一部分研究了声目标的定位技术，分为平面目标定位和空中目标定位两种。
The other part of the thesis discusses the target location problem which includes targets on the ground and in the sky.
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