They were sorely needed because the work was so strenuous and dangerous, and it was carried on in such a remote part of the country that the railroad company could not find other laborers for the job.

• 由于这项工作艰辛而危险，并且是在这个国家如此偏远的地区进行，以致于铁路公司找不到修建铁路的其他劳力，因而非常需要这批人。