In 1945 C.J.Ghu turned his attention to rotorcraft and designed a co-axial helicopter, known as the Humming Bird Model A.是什么意思_In 1945 C.J.Ghu turned his attention to rotorcraft and designed a co-axial helicopter, known as the Humming Bird Model A.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句