：in the past century

：in the past century over the past century意思 为什么over the years用现在完成时 而it 's about changes in Beijing over the past century不用呢 in the early nineteenth century. During the past century需要涉及的时态是什么啊? in the past造句 Memory in the past in the past two in the past翻译 in the past long in the past few Trapped in the past in the past 英语翻译despite all the evidence of the extraordinary improvements in public health during the past century,surveys show that we experience more symptoms. 英语翻译despite all the evidence of the extraordinary improvements in public health during the past century,surveys show that we experience more symptoms. 麻烦告诉下为什么：There___ great changes in Beijing in the past century.A.has been B.have been C.was D.were 请问为什么不能选D 这个从句的句子成分分析,that have taken place in English-language newspapers during the past quarter-century.就是说明主谓宾定状补表语什么的, century 的含义公元224年属于in the second century 还是third century?