For an encore, he sang an unaccompanied folk song.应观众再唱一曲的要求, 他清唱了一首民歌.She is humming a folk song that I never heard before.她在哼一首我以前从未听过的民歌.She was asked to sing a folk song by a large audience.许多观众要求她唱一首民歌....
They also secrete a waxy, transparent substance called cutin.它们还分泌蜡质的透明物质,称作角质.Cutinization The impregnation of a plant cell wall with cutin.角化作用(角质化):角质陆续侵渗植物细胞壁的过程.It will get better result after removing the cutin.祛角质...