We are still in the exploratory stages of this project, although what's noteworthy is that East Asians on average sleep about an hour and a half less each night than North Americans do.
我们仍然在这个项目的探索阶段，尽管值得注意的是，东亚人平均每晚比北美人少睡一个半小时。
2
The Yangtze river is a natural barrier to the north-east.
长江是东北方向的一道天然屏障。
《牛津词典》
3
It is suggested that 5,000-6,000 years ago people in the Middle East and North Africa started to allot specific lengths of time to tasks.