Round bottemed flask with bung and tube. black and white diagram / outline. Also with ink drop to show thermal expansion From GENERAL SCIENCE BY BERTHA M. CLARK, PH.D. (Gutenberg EBook 16593) 瓶 桶口 圆 bottemed 圆底烧瓶
black bottom science diagram white round flask lineart tube trace classroom experiment with bottemed bung Round Bot Flask clip art 一轮 瓶 桶口 圆 Bot 烧瓶剪贴画