presence
n.出席，到场，存在;仪表，仪态
Your presence is requested at the club meeting on Friday.敬请出席于周五举行的俱乐部会议。
present
a.出席的;现在的 n.现在;礼物 vt.赠(送)
the gases present in the earth’s atmosphere地球大气中存在的气体
presently
ad.不久，一会儿;现在，目前
The doctor will be here presently.医生一会儿就到。
preserve
vt.保护，维持;保存，保藏;腌制
We must encourage the planting of new trees and preserve our existing woodlands.我们必须鼓励栽种新树木，同时也要保护现有的林地。
