志愿服务的原则是？
参考答案：
自愿参加、量力而行、讲求实效、持之以恒。
— Look at the sign on the right.
— Oh, smoking ____ here. [ ]
A. doesn't allow
B. isn't allowed
C. didn't allow
D. wasn't allowed
制定小流域综合规划必须达到的六个目的是什么？
