sing

sing, hum

这两个动词均含“唱”之意。
sing: 普通用词，泛指一般的歌唱或发出悦耳的声音。
hum: 指闭着双唇而不唱出字来，低语般的哼唱。

动词 sing:

1. deliver by singing
2. produce tones with the voice
3. to make melodious sounds
4. make a whining, ringing, or whistling sound
   同义词：whistle
5. divulge confidential information or secrets
   同义词：spill the beans, let the cat out of the bag, talk, tattle, blab, peach, babble, babble out, blab out

1. She'll sing if we put the pressure on.
   我们给她些压力她就会讲出来。
2. She was singing a lullaby to her child.
   她正在给孩子唱摇篮曲。
3. Birds sing loudest in the early morning.
   鸟儿在清晨高声歌唱。