They worked together and so______the task in a month.
【正确答案】 B
【答案解析】解析:本题须弄清以carry为中心的四个短语动词的意思。A项carry out意为"实行,执行(计划,任务)",B项carry through意为"实现,完成",C项carry on意为"继续,经营",D项Carry off意为"拿走,赢得(奖章)"。根据题意,B项答案最为合适。