循环氨水带油上焦炉的原因可能是()
A、分离器油位过高
B、循环氨水流量过大
C、停留时间过短
D、分离器上部筛网损坏
参考答案:A, B, C, D
函数y = (2x+1) 3在x = 0处的导数是
A.0
B.1
C.3
D.6
What do you advice for____ the dirty mark from my bag?[ ]
A. removing
B. moving
C. getting
D. bringing