六、阅读理解。
主题群:自然生态
子主题:生态特征
语篇类型:说明文
难度:★★
Though oceans cover about 71% of the earth's surface, there's still a lot we don't know about them. Only about 20% of the seafloor has been mapped, and the remaining 80% is still a secret to us. Some scientists even think that 91% of sea animals have yet to be discovered.
So why do we know so little about the deep sea? Well, getting to those depths is very difficult and requires high technology that simply didn't come into being for most of human history. The first submarine(潜水艇), for example, was built in 1620. In fact, for a long time many scientists didn't even think that there could be any life at depths greater than 550 metres and didn't see much need to explore the deep sea. However, this changed in 1862 when life was discovered as far down as 945 metres below sea level with the help of a digging machine. Later, around 4,700 species(物种) unknown before from the ocean floor were discovered.
Since then, high technology has been developed to help explore the deep sea, including satellites. But why is deep-sea exploration still so difficult? Well, at greater depths it is freezing, everything is completely dark, and the pressure can be over 1,000 times greater than that on the surface.
Though we have the difficulties, it's important that we understand the seas. They help control the earth's temperature and produce oxygen（$\ce{O_{2}}$） in the air. They can also provide us with information about climate change. Our future depends on learning more about our oceans, and it is possible for us to really understand what is ongoing below the surface.
1. Why are some numbers listed in Paragraph 1?
A. To introduce how important oceans are.
B. To discuss why sea animals have yet to be discovered.
C. To explain that oceans cover a large area of the earth.
D. To show that we have only a little understanding of oceans.
2. What does the underlined word "They" in the last paragraph refer to?
A. Sea animals.
B. The seas.
C. The satellites.
D. Many scientists.
3. What can we learn from the text?
A. It is difficult to build a submarine.
B. The seas have a strong influence on our future.
C. The seas have no lives at a depth of 550 metres.
D. It is easier to go into the deep sea than we think.
主题群:自然生态
子主题:生态特征
语篇类型:说明文
难度:★★
Though oceans cover about 71% of the earth's surface, there's still a lot we don't know about them. Only about 20% of the seafloor has been mapped, and the remaining 80% is still a secret to us. Some scientists even think that 91% of sea animals have yet to be discovered.
So why do we know so little about the deep sea? Well, getting to those depths is very difficult and requires high technology that simply didn't come into being for most of human history. The first submarine(潜水艇), for example, was built in 1620. In fact, for a long time many scientists didn't even think that there could be any life at depths greater than 550 metres and didn't see much need to explore the deep sea. However, this changed in 1862 when life was discovered as far down as 945 metres below sea level with the help of a digging machine. Later, around 4,700 species(物种) unknown before from the ocean floor were discovered.
Since then, high technology has been developed to help explore the deep sea, including satellites. But why is deep-sea exploration still so difficult? Well, at greater depths it is freezing, everything is completely dark, and the pressure can be over 1,000 times greater than that on the surface.
Though we have the difficulties, it's important that we understand the seas. They help control the earth's temperature and produce oxygen（$\ce{O_{2}}$） in the air. They can also provide us with information about climate change. Our future depends on learning more about our oceans, and it is possible for us to really understand what is ongoing below the surface.
1. Why are some numbers listed in Paragraph 1?
A. To introduce how important oceans are.
B. To discuss why sea animals have yet to be discovered.
C. To explain that oceans cover a large area of the earth.
D. To show that we have only a little understanding of oceans.
2. What does the underlined word "They" in the last paragraph refer to?
A. Sea animals.
B. The seas.
C. The satellites.
D. Many scientists.
3. What can we learn from the text?
A. It is difficult to build a submarine.
B. The seas have a strong influence on our future.
C. The seas have no lives at a depth of 550 metres.
D. It is easier to go into the deep sea than we think.
答案：1. D 推理判断题。根据"Though oceans cover about 71% of the earth's surface, there's still a lot we don't know about them."可知,列举的数字表明,尽管海洋覆盖地球表面的71%左右,但是我们对海洋仍然知之甚少。
2. B 代词指代题。根据"Though we have the difficulties, it's important that we understand the seas. They help..."可知,虽然有困难,但了解海洋是很重要的。此处They指代上文提到的海洋。
3. B 推理判断题。根据"Our future depends on learning more about our oceans, and it is possible for us to really understand what is ongoing below the surface."可知,海洋对我们的未来有很大影响。
2. B 代词指代题。根据"Though we have the difficulties, it's important that we understand the seas. They help..."可知,虽然有困难,但了解海洋是很重要的。此处They指代上文提到的海洋。
3. B 推理判断题。根据"Our future depends on learning more about our oceans, and it is possible for us to really understand what is ongoing below the surface."可知,海洋对我们的未来有很大影响。
解析：
【分析】
拿到这篇阅读理解，首先先明确三个题型分别是推理判断题、代词指代题、细节推理题：做第1题时先定位到第一段的段落主旨句，再看所有列举数字的共同指向，不要只盯着单个数字片面判断；做第2题代词指代题时，直接往前找距离划线词最近的核心复数名词，再结合代词后描述的功能验证指代是否合理；做第3题时逐个把选项和原文内容比对，排除明显和原文矛盾、无中生有的错误选项，就能选出正确答案。
【解析】
1. 第1题：定位到第一段，段落首句点明核心“尽管海洋覆盖约71%的地球表面，我们对海洋仍有大量未知”，后续列举的仅20%海床被测绘、剩余80%海床仍是秘密、91%海洋动物尚未被发现的数字，共同作用是佐证人类对海洋的认知非常有限。
排除错误选项：A选项第一段完全没有介绍海洋的重要性，不符合；B选项第一段没有讨论海洋动物未被发现的原因，不符合；C选项仅第一个数字能体现海洋占地球面积大，其余数字和面积无关，表述片面。最终选D。
2. 第2题：定位到最后一段，划线词They的前一句核心表述为“尽管我们面临很多困难，了解海洋是十分重要的”，紧接着后文描述They可以调节地球温度、产出空气中的氧气、提供气候变化相关信息，这些都是海洋的功能，因此They指代前文提到的the seas。
排除错误选项：A海洋动物无法完成调节全球温度、产出氧气的作用；C卫星是探索深海的工具，不符合功能描述；D科学家是人类，不可能实现这些自然相关的功能，最终选B。
3. 第3题：逐个比对选项和原文内容：
A选项原文仅提到第一艘潜水艇1620年被建造，没有提及建造潜水艇难度高的相关表述，属于无中生有；
B选项对应原文最后一句“Our future depends on learning more about our oceans”，说明人类的未来和海洋高度相关，海洋对我们的未来有很强的影响，表述正确；
C选项原文提到早期科学家误以为550米深度以下没有生命，后续已经在945米深度发现了生命，该表述和原文矛盾；
D选项原文明确说明深海环境极寒、完全黑暗、压强是地表的1000倍以上，探索难度极高，该表述和原文矛盾。最终选B。
【答案】
1. D 2. B 3. B
【知识点】
阅读理解推理判断，代词指代辨析，细节信息比对
【点评】
本篇属于自然生态主题的说明类阅读，整体难度适中，重点考察学生快速定位原文信息、结合段落主旨判断写作意图的能力，易错点是第1题容易只看到第一个71%的数字误选C选项，解题时要注意整合段落所有信息，不要被局部内容误导。
【难度系数】
0.7
拿到这篇阅读理解，首先先明确三个题型分别是推理判断题、代词指代题、细节推理题：做第1题时先定位到第一段的段落主旨句，再看所有列举数字的共同指向，不要只盯着单个数字片面判断；做第2题代词指代题时，直接往前找距离划线词最近的核心复数名词，再结合代词后描述的功能验证指代是否合理；做第3题时逐个把选项和原文内容比对，排除明显和原文矛盾、无中生有的错误选项，就能选出正确答案。
【解析】
1. 第1题：定位到第一段，段落首句点明核心“尽管海洋覆盖约71%的地球表面，我们对海洋仍有大量未知”，后续列举的仅20%海床被测绘、剩余80%海床仍是秘密、91%海洋动物尚未被发现的数字，共同作用是佐证人类对海洋的认知非常有限。
排除错误选项：A选项第一段完全没有介绍海洋的重要性，不符合；B选项第一段没有讨论海洋动物未被发现的原因，不符合；C选项仅第一个数字能体现海洋占地球面积大，其余数字和面积无关，表述片面。最终选D。
2. 第2题：定位到最后一段，划线词They的前一句核心表述为“尽管我们面临很多困难，了解海洋是十分重要的”，紧接着后文描述They可以调节地球温度、产出空气中的氧气、提供气候变化相关信息，这些都是海洋的功能，因此They指代前文提到的the seas。
排除错误选项：A海洋动物无法完成调节全球温度、产出氧气的作用；C卫星是探索深海的工具，不符合功能描述；D科学家是人类，不可能实现这些自然相关的功能，最终选B。
3. 第3题：逐个比对选项和原文内容：
A选项原文仅提到第一艘潜水艇1620年被建造，没有提及建造潜水艇难度高的相关表述，属于无中生有；
B选项对应原文最后一句“Our future depends on learning more about our oceans”，说明人类的未来和海洋高度相关，海洋对我们的未来有很强的影响，表述正确；
C选项原文提到早期科学家误以为550米深度以下没有生命，后续已经在945米深度发现了生命，该表述和原文矛盾；
D选项原文明确说明深海环境极寒、完全黑暗、压强是地表的1000倍以上，探索难度极高，该表述和原文矛盾。最终选B。
【答案】
1. D 2. B 3. B
【知识点】
阅读理解推理判断，代词指代辨析，细节信息比对
【点评】
本篇属于自然生态主题的说明类阅读，整体难度适中，重点考察学生快速定位原文信息、结合段落主旨判断写作意图的能力，易错点是第1题容易只看到第一个71%的数字误选C选项，解题时要注意整合段落所有信息，不要被局部内容误导。
【难度系数】
0.7