在九年级上册的英语学习中，Unit 2的内容围绕着“环境保护”这一主题展开，旨在通过完成句子的练习帮助学生更好地掌握重点词汇和语法知识。以下是一些精心设计的完成句子练习题，供学生们参考和练习。

1. We should ________ the environment because it is important for our future.

A. protect B. destroy C. ignore D. waste

2. Recycling paper can help reduce the amount of waste and ________ trees.

A. cut down B. save C. plant D. burn

3. The government has taken many measures to ________ air pollution.

A. increase B. control C. ignore D. cause

4. Everyone should play a role in making the world a ________ place.

A. cleaner B. dirtier C. noisier D. smaller

5. If we don't take action now, the consequences will be ________.

A. serious B. minor C. temporary D. positive

6. Many people believe that ________ energy is the key to solving environmental problems.

A. fossil B. renewable C. nuclear D. coal

7. It's everyone's responsibility to ________ litter on the ground.

A. throw B. pick up C. leave D. recycle

8. The ________ of plastic bags has been banned in many cities to reduce pollution.

A. use B. production C. sale D. disposal

9. Trees not only provide us with oxygen but also help ________ the climate.

A. change B. improve C. worsen D. ignore

10. Education plays an important role in raising people's ________ about environmental protection.

A. awareness B. ignorance C. concern D. doubt

这些题目涵盖了Unit 2的核心知识点，包括环境保护相关的词汇和表达方式。通过反复练习，学生可以加深对课文的理解，并提高语言运用能力。希望同学们能够认真完成这些练习题，为即将到来的考试做好充分准备。同时，也希望大家能将所学知识应用到日常生活中，为保护我们的地球尽一份力。