But in any event, archeological sites from the Olmec and Shang cultures only began to be discovered at the end of the last century, and systematic excavations were not made until the 1930s and 40s.
不論如何，奧爾梅克與殷商文化遺址都是在上世紀末才被人發現，在本世紀三、四十年代開始有系統的發掘。