You can see the digestive tract in the middle, and the caterpillar's breathing tubes.

你可以看到中间的消化道和毛毛虫的呼吸管。

But beef can be contaminated if a butcher punctures the digestive tract.

但是如果屠夫刺破消化道， 牛肉就会被污染。

IBD is often linked to an overactive immune system, where the body's own immune cells attack the digestive tract.

IBD通常与过度活跃的免疫系统有关，其中身体自身的免疫细胞攻击消化道。

A sea cucumber is essentially a brainless, fleshy form surrounding a digestive tract, bookended by a mouth and an anus.

海参本质上是一种无脑的肉质形式， 围绕着消化道，由嘴巴和肛门构成。