这篇文章的标题清楚地概括了主要内容。

The ___heading of this article clearly summarizes the main content.

飞机调整了航向以避免恶劣天气。

The plane adjusted its ___heading to avoid the bad weather.

工人们沿着狭窄的巷道进入煤层。

The workers followed the narrow ___heading to access the coal seam.