bird-song

n [U] musical cry of birds 鸟的婉转啼鸣; 啁啾.

biologist, biology, biomedical, bionic, bionics, biopsy, biorhythm, bioscope, biotechnology, bipartisan, bipartite, biped, biplane, birch, bird, bird of paradise, bird of passage, bird of prey, bird sanctuary, bird-bath, bird-table, bird-watcher, birdbrained, birdcage wire, birdie, birdlime (also lime), birds, birdseed, biretta, Birmingham, birth, birth certificate, birth rate, birth-control, birthday, birthmark, birthplace, birthrate, birthright, biscuit,