Question: When was the final tunnel joint installed on the only way across the Lingdingyang other than the Humen Pearl River Bridge?
Sentence (from "Lingdingyang"): The Humen separates Lingdingyang and Shiziyang the upper channel of the Pearl River Estuary in the north and the Jiuzhouyang the lower channel of the Pearl River Estuary at the southern tip of Xiangzhou and the western tip of Lantau all the way till the southern end of the Wanshan Archipelago.
Relevant evidence: No