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
science diagram round burner flask air bubbles grayscale trace heat classroom experiment bunsen bottemed thermal expansion Thermal Expansion Of Air clip art 热 扩大 灰度 热空气膨胀的剪贴画
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