语法与词汇 Thousands of tons were extracted before 1875, when it was first noticed that the tar contained fossil remains. Major excavations were undertaken that established the significance of this remarkable site.
【正确答案】 D
【答案解析】句意：人们首次注意到焦油中包含了化石遗留物之后，直至1875前已经提取了成千上万吨焦油。大型挖掘工程的开展确立了此处遗址的重要地位。notice意为“注意到”，与observe意思相近。predict预测。announce宣告。correct改正。因此，本题正确答案为D。