1. He has suffered from a disorder of the digestive system.
    他已患消化系统失调。

2. Some iron is lost in sweat, and, for unknown reasons, intense endurance exercise is sometimes associated with bleeding of the digestive system.
    有些铁离子随汗液流失。另外，由于某些未知的原因，高强度的耐力运动有时是与消化系统内出血联系在一起的。

3. Over the periods their saliva, a mild, digestive juice like our own,
    蛇的唾液本来和我们人的消化液一样柔和，但经过漫长的时间，