举高消防车使用()后,应用清水对管系进行清洗,并开启各阀,放尽残存积水。
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I wish to inform you that as a result of negligence on the part of the lighter Susan when shifting at 0910 hrs this morning,the lower platform of the gangway was().
A. break
B. broke
C. breaked
D. broke
30kg/m钢轨的垂直磨耗一般不超过()。
A. 9mm
B. 7mm
C. 15mm
D. 20mm