Farvitron
线振质谱计
🗣️ 情景例句
Play it safe.
做事要稳妥。
John has built up his own business.He owns a hotel.
约翰建立了他自己的生意，他拥有一家宾馆。
Don't pull the chairs about,boys!
不要把椅子拖来拖去，孩子们！