priorto是个介词短语吧
prior to是介词短语。 在……之前；居先 It is important to enrich the soil prior to planting. 栽种之前给土壤施肥很重要。 This duty is prior to all others . 这个职务比其他一切职务都重要。 We received no notification prior to today 's date . 我们在今日之前未获通知。 I called on her prior to my...