根据所给的首字母提示，完成短文。

Yesterday I visited the Baihai Zoo．I was s­­­­­­  小题1:   to find few people there．Zoos are very important places．They p  小题2:   homes for many endangered animals．They also help to educate the public about caring f  小题3:   them．If we don’t s  小题4:   our zoos, they won’t have e  小题5:   money to take care of so many fine animals．Therefore, people should go and visit the zoos m  小题6:   often to learn about animals and help to protect them better．

H  小题7:  , some people don’t think so．They think zoos are t  小题8:   places for animals to live．“I’ve visited a lot of zoos in my life, and I have never seen o  小题9:    I liked or one that was suitable for animals to live in．” Jenny said．‘The animals are k   小题10:    in small cages and can hardly move at all．What’s more, they are only given food once a week．That’s terrible．”

（10分）【环境保护】

阅读图文材料，回答下列问题。

材料一 据水利部门对全国约700条大中河流近l00000千米河长检测的结果表明，我国现有河流近一半的河段受到污染，l／10的河流长期污染严重，河水已失去使用价值。我国将面临资源型缺水和水质型缺水双重压力，水资源问题将成为21世纪制约中国社会经济发展的重要因素，因此，保护水环境已成为我国的当务

材料二 下图为中国7大水系水质差别对比图(2003年)

（1）我国7大水系中，水污染最严重的是______________ 水系，从空间分布看，______地区的水质较好。（4分）

（2）改善我国河流水质的有效措施有哪些? （6分）