sentence: Some flasks have more than one neck and opening at the top.
sentences_before: A 'flask' is a type of container made of glass. They are a common piece of apparatus used in laboratories. Their shape depends on what they are used for, but they usually consist of a wider body, which contains the materials, and a more narrow neck with an opening at the top. The opening is the way to insert materials into the body.
concept_name: flask
headings: Flask
categories: Laboratory equipment Glass Containers