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
