加热炉初次建立燃料油炉前压力时燃料油进出装置已经建立燃料油炉前循环。（）
参考答案：对
Our school is having a sports meeting. Someone _____ here already. [ ]
A. arrived
B. have arrived
C. has arrived
( )是物资采购贯穿始终的准绳。
A．适时适量保证供应
B．保证采购物资的质量
C．费用最省
D．库存最低
