单口 meaning in English

simple aperture

Single opening exhaust valves
单口排气球
The network fax portion has the same high quality function as the standard version
网络传真功能单口，网络传真功能与标准版相同。
As follows : first , control programe is simple ; second , the cost of control and ration of double are lower : third , letters ca n ' t be damaged easily
采用单向多口控制，与进口设备中的循环单口控制相比，控制程序简单，控制成本低，出双率低，不易损坏信件。