The weather was warm, the food was inviting and the view was pretty — ____ we had a pleasant holiday.

A．exactly

B．meanwhile

C．finally

D．altogether

加臭工作可由SCADA测点系统中的PLC自动控制完成，PLC可根据采集到的流量讯号控制加臭机（使用A/D模块，输出4-20mA电流信号），实现（）加臭，控制算法可根据要求编制。

A.自动

B.手动

C.自动和手动

D.以上都不正确