五、根据背景材料,完成下列任务
Built over 2,200 years ago during the Qin Dynasty, the Dujiangyan Irrigation(灌溉) System is one of the world's oldest and most famous water projects. Located on the Min River, it was designed by the ancient engineer Li Bing in 256 BC to control flooding and provide water for farming in the Chengdu Plain.
The system splits the river into inner and outer channels. In dry seasons, $60\%$ of the water flows into the inner rivers to irrigate farms. During rainy seasons, most water is directed to the outer channel, preventing floods. This smart design helped transform the region into productive farmland.
However, silt carried by the river required regular cleaning of the riverbed. When Dujiangyan was first built, Li Bing placed stone markers called Shima to show how deep to dig. Later, iron sticks known as Wotie replaced the stones as digging guides. Each dry season, people dug until they reached the Wotie.
The tradition of maintaining the riverbed has lasted over 2,000 years. Today, several Woties from different eras still lie underwater. Though modern tools are now used, these iron sticks remain powerful symbols of ancient wisdom, passing the knowledge of Li Bing across generations.
任务一:根据文章内容,选择最佳选项。
()24. Why was the Dujiangyan Irrigation System built?
A. To make the Min River look beautiful.
B. To control floods and provide water for farms.
C. To help ships travel more easily.
D. To create a place for fishing.
()25. What can we infer about the Wotie?
A. They were used to measure water speed.
B. They showed people how deep to dig during cleaning.
C. They were placed to honour Li Bing.
D. They helped direct fish into the inner river.
()26. What is the main idea of the passage?
A. The Dujiangyan system is an ancient smart water project that is still used today.
B. Li Bing was a famous Chinese engineer.
C. The Ming Dynasty improved the Dujiangyan system.
D. Cleaning the riverbed is very important.
任务二:根据文章内容,匹配单词释义。
()27. Shima
A. Small soil pieces left by water.
()28. Wotie
B. Stone markers used in ancient times.
()29. Silt
C. Iron sticks used to guide digging.
任务三:根据文章内容,回答下列问题。
30. What problem did silt cause for Dujiangyan? (Answer within 20 words)

24.B
25.B
26.A
27.B
28.C
29.A
30. It made the riverbed shallower, so people had to clean it every year.（答案不唯一，言之有理即可）

【分析】
本题为英语阅读理解题，包含细节理解、主旨大意、词义匹配及简答题四类题型。解题思路如下：1. 细节题（24、25、30）：定位原文对应段落，提取题干关键词，匹配原文信息得出答案；2. 主旨题（26）：梳理全文核心内容，排除片面选项；3. 词义匹配题（27-29）：找到原文中对应词汇的定义描述完成匹配；4. 简答题（30）：结合原文关于泥沙影响的表述，用简洁语言作答。
【解析】
24. 细节理解题：根据第一段“designed by the ancient engineer Li Bing in 256 BC to control flooding and provide water for farming”可知，都江堰建造目的是防洪和提供农业用水，故选B。
25. 细节理解题：根据第三段“iron sticks known as Wotie replaced the stones as digging guides. Each dry season, people dug until they reached the Wotie”可知，Wotie是挖河床时的深度指引，故选B。
26. 主旨大意题：全文围绕都江堰这一古老智慧水利工程展开，介绍其设计、维护及意义，A选项符合主旨；B仅提及李冰，C时间错误，D仅为细节，均排除，故选A。
27. 词义匹配题：根据第三段“Li Bing placed stone markers called Shima”可知，Shima是古代石制标记，对应B。
28. 词义匹配题：根据第三段“iron sticks known as Wotie replaced the stones as digging guides”可知，Wotie是挖渠指引的铁条，对应C。
29. 词义匹配题：根据第三段“silt carried by the river required regular cleaning of the riverbed”可知，silt是泥沙，对应A。
30. 简答题：根据第三段“silt carried by the river required regular cleaning of the riverbed”，可知泥沙导致河床需定期清理，答案为It made the riverbed need regular cleaning every dry season.（符合字数要求即可）
【答案】
24.B 25.B 26.A 27.B 28.C 29.A 30. It made the riverbed need regular cleaning every dry season.
【知识点】
英语阅读理解细节题、主旨大意题、词义匹配题
【点评】
本题以中国古代水利工程都江堰为背景，题型覆盖英语阅读核心考点，既考查学生信息定位、主旨理解及词义辨析能力，又融入传统文化知识，兼具练习价值与文化意义。
【难度系数】
0.6