translation.en: But when I started on this back in 2007, there wasn't even a definitive list of how many shapes there were, nor was there a strong sense of whether the same ones appeared across space or time.
translation.zh: 但在2007年我开始从事这项研究时， 甚至没有一份关于这些几何符号的明确清单， 也没有人强烈地意识到 是否同样的符号 曾在不同的时间或地点存在过。