题目内容：
Most cities in the country have introduced "Clean Air Zones" _____ factories and households are only allowed to burn smokeless fuel.A、thereby
B、whereby
C、by
D、hereby
参考答案：
选择题：Most cities in the country have introduced "Clean
- 题目分类：华北水利水电大学-大学英语
- 题目类型：选择题
- 查看权限：VIP
A、thereby
B、whereby
C、by
D、hereby