他以颤声演唱了民歌.He quavered out folk songs.有些鸟颤声鸣唱.Some birds trill their songs.她颤声朗诵给他听卢泊·布鲁克的十四行诗.In her trembling voice she read to him Rupert Brook's sonnet....

“颤声”的英语可以翻译为：quaver，trill，warble ...