A pigeon emerges, wings flapping noisily, from the tower.一只鸽子从塔里钻出来，扑扑地拍打着翅膀。A pigeon strutted along the roof, cooing rhythmically.一只鸽子沿着屋顶大摇大摆地走, 有节奏地咕咕叫.The pigeon homed from a distance of 100 miles.鸽子从百英里之外返回窝巢....pig...
The Frequency Shift Keying modulation is widely used in HF digital communication.移频键控是短波数字通信中常用的一种调制方式.Her sister carried with her most of the grimness of shift and toil.她姐姐身上还带着艰辛操劳的痕迹.Before deselecting shift the selec...