***于2006年2月14日在《扎扎实实规划和推进社会主义新农村建设》的讲话中指出，重视农业、农村、农民问题是我们党的一贯战略思想。历史事实证明，“三农”问题始终是关系党和人民事业的全局性和根本性问题。为此，同学们组织了一场以“三农”问题为主题的知识竞赛：

首先，请您作为参赛选手回答问题：

下列消化液中，不含消化酶的是

      Ruby, the artist, is an Asian elephant, She is17 years old. She lives in the zoo. Ruby has produced about 100 paintings since last year. She has made more than $ 40,000 for the zoo. Zoo leaders say Ruby first showed the talent (才能) about four years ago. Zoo workers watched her make the marks in the sand with her trunk. She rubbed (擦掉) out the marks, then made the new ones. The zoo worker gave her brushes and paints. Soon Ruby painted pictures.
       Newspaper reporters wrote Ruby, then people asked about buying her pictures. And in this way, she made a lot of money for the zoo. This is how Ruby does the paintings. A zoo worker holds different color paints. Ruby touches the colors she wants. Then the worker gives her brushes with the chosen colors in her trunk and Ruby begins painting.