open/ˈəʊpən/是第一个音节重读，末尾的音节是非重读音节，所以进行时加ing不双写: opening
His mouth was open and his eyes bugging .他嘴张着，眼珠都鼓了出来。
Nasa officials opened a broad inquiry .宇航局官员开始进行广泛调查。
The railway was opened to traffic last year .这条铁路是去年通车的。
My little cousin， maggie， opened the door .我的小表妹麦吉打开了门。
It 's easy to open a shop but hard to keep it open .创业容易守业难。
The open spaces differ according to aspect .开敞空地随方位而不同。
The conference was solemnly openedyesterday .会议于昨天隆重开幕。
Out of the blue， he opened up a business .出人意料他竟做起了生意。
We ventilate a room by opening windows .我们开窗以使室内空气流通。
I'm always open to a good idea .我对于良好的意见一向是乐于接受的。
双写加 ing的情况的条件之一 是 必须是重读音节listen 和open的重读音节 在前面，不在 sten 和pen 上，所以不双写
