此外,滑流的旋转和尾翼处下洗的变化也是重要的因素.Also important are the rotation of the slipstream and the change of downwash at the tail.总有一天,一场真正的暴雨,将骤然降下,洗尽街上所有的人渣.Someday a real rain will and wash all the scum off the streets....
天文学家能够测定每颗恒星的亮度。An astronomer can determine the brightness of each star.星星的光亮度各不相同.Stars vary in brightness.用18瓦的荧光灯灯泡有同样的亮度，而用电量却减少75％。With an 18-watt fluorescent bulb you get as much light but use 75% less electricity....