Ra在代号中仅用数量表示，单位为（）。 ["μm","cm","dm","nam"]
“客有为齐王画者，齐王问曰：‘画孰最难者？’曰：‘犬马最难。’‘孰易者？’曰：‘鬼魅最易’。”此段话出自（），这是中国美术理论发展过程中最早提出的关于（）的问题。
单纯词
No less than（）nobles of royal blood were killed in the Wars of the Roses. ["80","90","100","110"]
两组导轨在水平面内的平行度误差，应用（）来检验。 ["水平仪","轮廓仪","百分表","测微仪"]
合成词
