均质土坝最常用的土料有______。
A．砂质黏土
B．黏土
C．细砂
D．壤土
E．砂砾石
参考答案：A,E
An original mechanism to deal with conflicts is established in order to prevent overspilling of conflicts from one country into another country.
上下级保护间只要动作时间配合好，就可以保证选择性
