双相滴定法测定苯甲酸钠的含量时所用溶剂为
A.水-甲醇
B.水-冰醋酸
C.水-氯仿
D.水-乙醚
E.水-丙酮
参考答案:D
To our disappointment, the trip we had been looking forward to ________ in the pouring rain.[ ]
A.starting
B.start
C.to start
D.started
HIS的哪种显示方式的顶部窗口不显示航迹()?
A、MAP
B、PLAN
C、NAV
D、VOR/ILS