ⅰt的复数是什么

1\They decided to base the new company in York.
他们决定将新成立的公司总部设在约克郡。
2\They won by a single goal after extra time.
他们在加时赛中仅踢进一球即获胜。
3\The treatment they gave him did him more harm than good.
他们的治疗对他弊多于利。