firstly

1. ADV You use firstly in speech or writing when you want to give a reason, make a point, or mention an item that will be followed by others connected with it. 第一 (縯講、文章中用於列擧條目); 首先[ADV with cl/group]

The programme is now seven years behind schedule as a result, firstly of increased costs, then of technical problems. 該計(jì)劃現(xiàn)在比預(yù)定的計(jì)劃晚了7年，首先是因爲(wèi)費(fèi)用增加，其次是由於技術(shù)問(wèn)題。