Migrating birds filled the pale sky.灰白的天空中满是迁徙的飞鸟。The mudflats offer a winter home to thousands of migrating swans.泥滩成为成千上万只迁徙的天鹅越冬的场所.Migrating birds have marvelouos directional sense.候鸟有非凡的方向辨别力。...
An impartial onlooker must be sought out.须问旁观冷眼人.The onlooker affirmed the fact to be true.这位旁观者断言这是事实.By the time the ambulance arrived, a crowd of onlooker had gathered.救护车赶到时, 围观的人已经很多了....