Ⅳ. Complete the sentences with relative pronouns which, that or who.
1. The small actions we take every day can greatly change the future of our beautiful earth.
2. The serious pollution is caused by human activities is destroying the home of living things.
3. Volunteers work hard to save wild animals bring hope to our broken ecosystem.
4. The perfect balance nature keeps for years is easily broken by careless human behaviour.
5. People realize the importance of nature will live a low-carbon life.
6. The lovely wild animals live peacefully in nature need our care and protection all the time.
7. Students form good green habits can make a small difference to the whole planet.
8. The green forests cover large parts of our planet can clean the air and cool the whole world.

1. that/which 2. that/which 3. who/that 4. that/which 5. who/that 6. that/which 7. who/that 8. which/that

【分析】本题考查定语从句中关系代词which、that、who的用法，解题思路为：①先确定每个句子中定语从句修饰的先行词（被修饰的名词）；②判断先行词指代的是人还是物；③根据规则：先行词指物时，关系代词用that或which；先行词指人时，关系代词用who或that，据此选出合适的答案。
【解析】1. 先行词是the small actions（指代物），故用that/which；2. 先行词是the serious pollution（指代物），故用that/which；3. 先行词是Volunteers（指代人），故用who/that；4. 先行词是the perfect balance（指代物），故用that/which；5. 先行词是People（指代人），故用who/that；6. 先行词是the lovely wild animals（指代物），故用that/which；7. 先行词是Students（指代人），故用who/that；8. 先行词是the green forests（指代物），故用which/that。
【答案】1. that/which 2. that/which 3. who/that 4. that/which 5. who/that 6. that/which 7. who/that 8. which/that
【知识点】定语从句，关系代词用法
【点评】本题为定语从句关系代词的基础考查题，核心是掌握先行词指人/物时对应关系代词的选用规则，属于初中英语必掌握的基础语法点，难度较低。
【难度系数】0.7

Ⅴ. Combine the two sentences with relative pronouns which, that or who.
1. The oceans cover over 70% of the earth's surface. They are crying out for help.
→ The oceans cover over 70% of the earth's surface are crying out for help.
2. Sea animals can't live with higher temperatures. They are suffering from global warming.
→ Sea animals are suffering from global warming.
3. Many animals live in the sea. They are disappearing.
→ Many animals disappearing.
4. People are worried about the oceans. There's a lot for them to do.
→ For people , there's a lot to do.
5. We must use green energy. It produces little or no greenhouse gases.
→ We must
6. Experts give useful advice. They study environmental protection.
→ Experts

1. that/which 2. that/which can't live with higher temperatures 3. that/which live in the sea are 4. who are worried about the oceans 5. use green energy that/which produces little or no greenhouse gases. 6. who study environmental protection give useful advice.

【分析】本题要求用关系代词that/which/who合并两个句子，解题思路为：①先确定每个句子中被修饰的名词（即先行词）；②判断先行词指代的是人还是物：指代物用that/which，指代人用who；③将第二个分句作为定语从句接在先行词后，调整句子语序，完成合并。
【解析】1. 先行词the oceans指物，用that/which，合并后为The oceans that/which cover over 70% of the earth's surface are crying out for help.
2. 先行词sea animals指物，用that/which，合并后为Sea animals that/which can't live with higher temperatures are suffering from global warming.
3. 先行词many animals指物，用that/which，合并后为Many animals that/which live in the sea are disappearing.
4. 先行词people指人，用who，合并后为For people who are worried about the oceans, there's a lot to do.
5. 先行词green energy指物，用that/which，合并后为We must use green energy that/which produces little or no greenhouse gases.
6. 先行词experts指人，用who，合并后为Experts who study environmental protection give useful advice.
【答案】1. that/which 2. that/which can't live with higher temperatures 3. that/which live in the sea are 4. who are worried about the oceans 5. use green energy that/which produces little or no greenhouse gases. 6. who study environmental protection give useful advice.
【知识点】定语从句（关系代词用法）、句子合并
【点评】本题聚焦定语从句中关系代词的基础应用，需学生准确判断先行词的指代类型（人/物），选择对应关系代词并调整语序，属于英语基础语法的常规考查，难度适中。
【难度系数】0.6