Create subregion if it does not already exist.

如果子区域尚不存在，创建子区域。

Create the subregion if it does not already exist.

如果子区域不存在，请予以建立。

The two-day Greater Mekong Subregion summit begins Sunday.

为期两天的大湄公河次区域首脑会议将于星期天开幕。

In this paper, a new concept of subregion function method is suggested.

本文提出了一个分区函数法的概念。

Open-door policy open lower airspace is not an easy process, step by step for the subregion.

低空域开放政策放开的过程并非一蹴而就，分区域分步骤进行。