单项选择题时下流行的居室设计中多运用天然木、石、藤、竹等材质质朴的材料，强调返朴归真，追求悠闲、舒畅的居室环境。此中设计风格属于
单项选择题— Is military service ____________ for every citizen in your country?— No, but almost all the boys between 18 and 25 have to. A. optional B. absolute C. compulsory D. alternative
