Main topsail: Shows the topsail added to the MainMast.
主上桅帆：显示了主桅上的上桅帆。
2
Mainmast top Looking down on the mainmast top, you can see through the lubber hole, and the dead-eyes.
主桅杆顶向下看去，在主桅杆桅楼，你可以看到穿过水手孔，和死眼。
3
Pathological changes for the mainmast facet osteoarthritis and spinal canal stenosis, and segmental instability, disc degeneration, spondylolisthesis and spinal ligament calcification, and other.