查看会员资料
用 户 名:io***
发送消息- Email:用户隐藏
- Icq/MSN:
- 电话号码:
- Homepage:
- 会员简介:
最新会员发布资源
hydroelectric-generator
- For more than 100 years, the simplest way to produce the volumes of falling water needed to make electricity has been to build a dam. A dam stops the natural fl ow of a river, building up a deep reservoir behind it. However, large dams and reservoirs