A. 对 B. 错
A. 停泵,向泵内灌液 B. 降低泵的安装高度 C. 检查进口管路是否有泄漏现象 D. 检查出口管路阻力是否过大
A. The condition of the buses. B. The types of washing machines. C. The music in the bars. D. The distance to classes.