飞机加油员通过（）来确认飞机油箱内是否含有杀菌剂。
A.测量油温
B.测量油料密度
C.查看航油化验单
D.飞行日志等文件
参考答案：D
-Mike, it's a pity you didn't come to last night's concert. Itwas really great!
-Really? If I _____ so busy, I would have gone with you. [ ]
A. hadn't been
B. weren't
C. shouldn't be
D. wouldn't be
在网络计划工期费用优化过程中，被缩短持续时间的工作应是( )。
A．直接费用最小的工作
B．直接费用变化率最小的工作
C．直接费用最小的关键工作
D．直接费用率最小的关键工作
