题目内容：
根据上述材料回答题：
In order to control air pollution in the past years, the EU has tried to __________.
参考答案：
答案解析：
单选题：根据上述材料回答题：In order to control air pollution in the past year
- 题目分类：英语四级
- 题目类型：单选题
- 查看权限：VIP
In order to control air pollution in the past years, the EU has tried to __________.