酸洗带钢表面CL离子含量要求小于()mg/m2每面
A.1.5
B.2.0
C.2.5
D.2.8
参考答案:A
I made a call to my parents yesterday. To my disappointment, ______ of them answered it. [ ]
A. either
B. none
C. neither
D. nobody
当机坪发生漏油时,加油员要立即(),关闭相应阀门。
A.停止加油
B.报告
C.继续加油
D.离开现场