CO2储罐压力高至()时储罐压缩机88RC-1A自动启动。
A.300psi
B.310psi
C.315psi
D.325psi
参考答案:B
John _____ knowledge of radio just by staying around the radio station. [ ]
A. caught on
B. worked up
C. took up
D. picked up
当加工中心长期不用时,应对其进行(),以保证再次使用时能运行正常。