根据营养素在消化道内被消化的先后顺序，药品“内层包衣”里的酶是____；

阅读短文，回答问题。

    Hello. I'm Peter. I'm a pupil. I go to school and study the boring knowledge(知识) every day now. I hope our school will change in the future. Schools will be different then. They will be under the sea, on high mountains and even in space. Robots will help us find books in the library and do our homework at home. We will use computers in all our lessons. They will help us see dinosaurs and other interesting things. We will have lessons with students from other countries. We will do a lot of things online together. We won't carry books to school. All our books will be on a small computer.

我国西部干旱地区收集和积储雨水，供生产和生活之用；伦敦和芝加哥利用收集和积储的雨水，满足冲厕所、洗马桶和清洗车辆。根据资料完成下题。
对于雨水的拦蓄和利用，对水循环产生直接影响的环节是(　　)