请阅读下面语篇，根据其内容，从所给的选项中选出能填入空白处的最佳选项，使其意思通顺，并在答题卡上将该项涂黑。选项中有一项为多余选项。

Imagine you have just cleaned your classroom. Then a strict teacher in school walks in, looks around, and gives you a big smile. ____29____ But this time the testers are birds.

In recent years, groups of rare (稀有的) birds like black storks and egrets have been seen along the Fenhe River. ____30____ These birds are very picky: they only live near clean water. Their arrival makes the river full of life.

Things were quite different in the past. There were few rare birds. ____31____ Because the river was polluted seriously. Then the government started a plan to bring the river back to life. Workers spared no effort to turn dirty water into clean water. ____32____ These wetlands helped clean the water. The water quality has improved a lot.

____33____ There are more plants growing in the wetlands. More and more birds choose the Fenhe River as their winter home.

When people take care of nature, nature gives back. The balance between humans and nature has become a reality in Shanxi.

A. Why was that?

B. They rest along the river banks playing happily.

C. The results of people’s hard work are easy to see.

D. The Fenhe River is the mother river of Shanxi Province.

E. That is exactly what is happening along the Fenhe River.

F. What’s more, they cleaned and added wetlands along the river.

1.29.

A

B

C

D

解析：选E。类比过渡句。上文：设想打扫干净教室，严格老师看到后露出微笑（代表：付出努力，得到检验者的肯定）。下文：But this time the testers are birds.“但这一次检验者是鸟类”。逻辑：用教室的小故事类比汾河生态故事。E 选项 That 指代前面整个小故事，把场景切换到汾河，完美衔接前后。排除其他：A 是提问，此处不需要问句；B 主语是鸟，但本段还没引出鸟类；F 是治理措施；C 讲成果，此时还没有讲治理结果；D 介绍汾河身份，上下文不需要介绍河流名称。

2.30.

A

B

C

D

解析：选B。细节描写句（代词指代线索）。上文：In recent years, groups of rare birds…have been seen along the Fenhe River. 近些年汾河边出现大批珍稀鸟类。代词They，复数，指代上一句的rare birds珍稀鸟类。本句描写鸟儿来到汾河之后的行为状态；后一句继续讲鸟儿习性：对生存环境很挑剔，只生活在干净水边。整段围绕 “归来的鸟类” 展开。排除：E 已经用掉；A 问句不符合语境；F 是治理动作；C 讲成果；D 介绍河流，和鸟儿状态无关。

3.31.

A

B

C

D

解析：选A。设问句（问答逻辑）。上文：Things were quite different in the past. There were few rare birds. 过去情况截然不同，珍稀鸟类几乎看不见。下文：Because the river was polluted seriously.因为河流被严重污染。关键信号词Because（因为），说明前面一定是提出问题。A 选项 Why（为什么）进行提问，形成 “提出问题 + 回答原因” 的问答结构。that指代 “过去几乎没有珍稀鸟类” 这件事。排除：B 写鸟的活动，但是过去几乎没有鸟；F、C 都是治理后的内容，还没讲治理；D 介绍河流，无法和 Because 构成问答。

4.32.

A

B

C

D

解析：选F。递进逻辑句（词汇复现线索）。上文：Then the government started a plan…Workers spared no effort to turn dirty water into clean water. 政府开启生态修复，工作人员全力把污水变净水。逻辑词What’s more 此外 / 而且，表示递进，继续列举政府、工人的第二项治理行动。下文：These wetlands helped clean the water.这些湿地帮助净化水质。词汇复现！F 选项里面的wetlands（湿地），和下句开头These wetlands完全对应，these就是指代 F 句刚提到的 wetlands。代词they指代上文中 workers 工人们。排除：剩余 C、D。C 讲成果，这里还在讲治理措施；D 介绍汾河，和 “these wetlands” 不呼应。

5.33.

A

B

C

D

解析：选C。段落主题总起句。空格为本段段首，是本段中心句。后文：There are more plants…More and more birds choose the Fenhe River as their winter home. 湿地植物变多，越来越多鸟类来此过冬。这些全部都是治理之后看得见的好结果。C 选项总领全段，引出后面一系列生态变好的现象。剩余未选 D：D 选项 “The Fenhe River is the mother river of Shanxi Province. 汾河是山西的母亲河”，全文没有任何位置可以插入这句话。文章重点讲汾河生态变迁，不需要介绍河流地位，作为多余干扰项。