问题补充:
Nearly half a million immigrants,many of them English—speaking,in the country during the last quarter of the nineteenth century.
A. have arrived
B. had arrived
C. arrived
D. have been arriving
答案:
A. have arrived
B. had arrived
(答案→)C. arrived
D. have been arriving
解析:考查句子结构。这个句子的主语是Nearly half a million immigrants,横线要填的是谓语动词,根据下文的时间可知应该使用过去时。句意:大约有50万移民,其中很多都是会讲英语的在19世纪最后的25年中来到了这个国家。