非本务牵引或在尾部担当补机任务的接触网作业车,应将GYK转入非本务状态,当转为本务机时必须()本务运行状态。
参考答案:立即恢复
Li Ming writes as _____ as Jenny. [ ]
A. good
B. better
C. well
D. best
砌块砌筑时,竖向灰缝的砂浆饱满度应不小于()。
A.79%
B.80%
C.90%
D.100%