Ⅰ. 用括号内所给单词的适当形式填空。
1. The beauty of nature is (mystery), so there are many things that need us to explore.
2. Our science teacher often says that (imagine) is the first step to great inventions.
3. In the future, people can travel to space by (spacecraft).
4. Several (billion) tons of waste are produced every year.
5. The project needs (cooperate) of all the members.

I. 1. mysterious 2. imagination 3. spacecraft
4. billion 5. cooperation

【分析】
本题为英语词汇适当形式填空题，需结合句子结构判断所需词性，再对括号内单词进行正确变形：1. 句子需形容词修饰名词，故将名词变形为形容词；2. 从句缺主语，需用名词，故将动词变形为名词；3. by后接交通工具，spacecraft单复数同形；4. several修饰billion时，billion用单数；5. need后缺宾语，需用名词，故将动词变形为名词。
【解析】
1. 句子结构分析：主语为The beauty of nature，系动词is后需形容词作表语修饰主语，因此将名词mystery转换为形容词mysterious；
2. that引导的宾语从句缺少主语，需用名词作主语，因此将动词imagine转换为名词imagination；
3. “by + 交通工具”为固定搭配，spacecraft单复数同形，无需变形，故填原形spacecraft；
4. several表示“几个”，修饰billion时，billion用单数形式，因此填billion；
5. need为及物动词，后需接名词作宾语，因此将动词cooperate转换为名词cooperation。
【答案】
1. mysterious 2. imagination 3. spacecraft 4. billion 5. cooperation
【知识点】
英语词性转换、名词的用法
【点评】
本题考查初中英语基础词汇变形，涉及词性转换、名词的数及固定搭配，题型基础，主要检验学生对核心词汇不同形式的掌握情况，难度较低。
【难度系数】
0.8

Ⅱ. 用方框中所给短语的适当形式填空。
on board set foot on in case
cooperate with fall asleep
1. The witness agreed the investigation.
2. Neil Armstrong was the first person to the surface of the moon.
3. The flight attendant welcomed us with a smile.
4. He packed extra batteries the flashlight stopped working.
5. He as soon as he lies down.

II. 1. to cooperate with 2. set foot on
3. on board 4. in case 5. falls asleep

【分析】
解答本题时，需先理解方框内各短语的含义，再结合每个句子的语法结构、固定搭配及时态要求，选择短语的适当形式填空。具体思路：1. 看到动词agree，回忆其固定搭配agree to do sth，确定空格用不定式；2. 看到结构the first person to do sth，确定不定式后用动词原形；3. 结合语境，固定表达welcome sb on board直接用短语原形；4. 结合句意，in case是连词表“以防”，直接用；5. 主语是第三人称单数he，一般现在时中动词用三单形式。
【解析】
1. 固定搭配agree to do sth，故填to cooperate with；
2. 结构the first person to do sth中，不定式后用动词原形，故填set foot on；
3. 固定表达welcome sb on board（欢迎某人登机/上船），故填on board；
4. 句意“他多装了电池以防手电筒坏了”，in case表“以防”，符合语境，故填in case；
5. 主语he是第三人称单数，一般现在时中动词用三单形式，fall asleep的三单为falls asleep，故填falls asleep。
【答案】
II. 1. to cooperate with 2. set foot on 3. on board 4. in case 5. falls asleep
【知识点】
固定短语搭配、动词不定式、一般现在时
【点评】
本题考查常用短语在具体语境中的形式运用，需掌握短语含义及相关语法规则（如不定式、时态），属于基础题型，适合巩固短语基础。
【难度系数】
0.6

Ⅲ. 阅读短文，选择最佳选项。
Have you ever wondered what it is like to be an astronaut? They face many challenges in space. Weightlessness is bad for human health. It can cause muscle and bone loss as well as vision（视觉）problems. Cosmic radiation（宇宙辐射）can harm their DNA. So, we need to understand how the human body changes in
space. But researchers don't have a good understanding of what actually happens to DNA in space. Studying telomeres（端粒）, the “end-parts” of chromosomes（染色体）that protect the ends of DNA, may help.
Researchers know that telomeres get shorter as people get older. Stress, smoking and unhealthy environments make telomeres shorter, too. The length of telomeres is connected with the risk of heart disease and cancer. This makes them important to study for human health.
In 2015, NASA did a study on the twin astronauts Scott and Mark Kelly. Scott spent a year on the International Space Station while Mark stayed on Earth. Researchers found Scott's telomeres increased in length while in space. His telomeres then quickly shortened when he returned to Earth. In fact, they were even shorter than before he went into space. The study gave researchers valuable new information about astronauts' health. To find out if the same changes happen during a shorter trip, another study was done on four astronauts who carried out a 3-day mission. Their telomeres were longer during spaceflight. But when they returned to Earth, their telomeres shortened quickly. They slowly returned to nearly normal length about 2 months later.
Both studies showed that space trips, even short ones, can change telomere length. Scientists think telomere length changes because of cosmic radiation exposure. Radiation, which is everywhere in space, can harm DNA. Spending more time in space also means more exposure. The International Space Station has protection in areas people use often. This helps protect the astronauts from some
radiation. But what if humans want to travel to or stay on other planets someday? We need a better method to reduce radiation harm.
Space is a dangerous environment. We don't know a lot about how it can influence people's health for a long time, especially their DNA. The more we know, the better we will be able to keep our astronauts healthy. By learning more about changes like telomere length, scientists can find ways to protect future space travellers. As space tourism becomes more common, this knowledge will be key to keeping people safe and healthy in space.
1. Which problem may weightlessness bring to astronauts in space? （）
A. Cancer.
B. Bone loss.
C. Heart disease.
D. Hearing problems.
2. Why is studying telomeres important according to the text? （）
A. Because it creates a healthy environment.
B. Because it helps reduce astronauts' stress.
C. Because it protects astronauts from radiation.
D. Because it shows how DNA changes in space.
3. What can we learn from the two studies? （）
A. Scott's telomeres returned to nearly normal length finally.
B. The time of spaceflight decides telomere length changes.
C. All the astronauts' telomeres were longer during spaceflight.
D. The twin astronauts both carried out a 1-year mission in space.
4. How does the writer show the influence of space on human health? （）
A. By listing numbers.
B. By providing examples.
C. By giving instructions.
D. By introducing backgrounds.
5. What is the main purpose of this text? （）
A. To compare life on Earth and in space.
B. To share stories about famous astronauts.
C. To explain how space affects DNA and health.
D. To introduce why space tourism develops rapidly.

III. 1－5 BDCBC

【分析】
本题为英语阅读理解题，需结合原文细节逐一分析各题：
1. 第1题：定位原文关于失重的描述，查找失重带来的问题，匹配选项；
2. 第2题：定位研究端粒重要性的相关语句，对比选项找出对应内容；
3. 第3题：结合两个研究的具体结果，逐一验证选项的正误；
4. 第4题：分析作者展示太空对健康影响的论证方法，判断选项；
5. 第5题：梳理全文核心内容，确定文章主旨，匹配选项。
【解析】
1. 第1题：根据原文第一段“Weightlessness is bad for human health. It can cause muscle and bone loss as well as vision problems.”可知，失重会导致骨骼流失，对应选项B。A（癌症）、C（心脏病）与端粒相关，D（听力问题）未提及，故选B。
2. 第2题：根据原文第一段“Studying telomeres... may help... researchers don't have a good understanding of what actually happens to DNA in space.”可知，研究端粒有助于了解DNA在太空的变化，对应选项D。A、B、C均未提及，故选D。
3. 第3题：根据第三段研究结果，Scott在太空时端粒变长，3天任务的宇航员太空时端粒也更长，故C正确；A选项Scott返回后端粒更短，未回到正常；B选项原文未表明飞行时间决定端粒变化；D选项仅Scott在太空一年，Mark在地球，故选C。
4. 第4题：作者通过NASA双胞胎研究、3天任务宇航员研究两个实例，展示太空对健康的影响，属于举例子的论证方法，故选B。A（列数字）、C（给说明）、D（介绍背景）均不符合，故选B。
5. 第5题：全文围绕太空对DNA和健康的影响展开，通过端粒研究说明相关变化，主旨为解释太空对DNA和健康的影响，故选C。
【答案】
BDCBC
【知识点】
英语阅读理解、细节理解、主旨大意
【点评】
本题考查英语阅读理解的核心能力，包括细节查找、推理判断和主旨归纳，要求学生精准定位原文信息，结合选项排除错误内容，整体难度适中，适合中等水平学生作答。
【难度系数】
0.6