英語翻譯：

例句：

1. 一旦戰(zhàn)爭爆發(fā)，許多國家都要受到波及。
   If a war broke out, many other countries will be affected.
2. 元旦是一個親屬團聚的日子。
   New Year's Day is a day for family reunion.
3. 一旦你覺得發(fā)燒就吃這藥片，每天3次。
   Once you feel feverish, take these pill three times a day.