Building a neon sign is an art practiced by professionals trained on the job to mold glass tubes into decorative shapes and letters.
2018年6月四级真题（第一套）阅读 Section A
Once you are done demonstrating whatever concept was in the textbook, you throw away the pipe cleaners, the straws, the cardboard tubes.
2019年6月四级真题（第三套）阅读 Section B
They fill these tubes with gases that glow when electrified.
2018年6月四级真题（第一套）阅读 Section A
英语六级真题
Kasselman wants to build an array of solar magnifying mirrors at one end of the line to collect and focus heat onto water-filled tubes.
2018年12月六级真题（第二套）听力 Section C
They hope to reduce both the number of components needed in a construction job and their weight一by replacing solid supports with hollow tubes, for example.
2019年6月六级真题（第三套）阅读 Section A
柯林斯高阶英汉双解学习词典释义
N-COUNT
管子;管;管状物
A tube is a long hollow object that is usually round, like a pipe.