串错了字twoice-->twice
Once代表一次,曾经,一旦
--副词adverb
--名词noun
--连接词conjunction
1)Iseethemonceeverytwomonths.
2)Onceisenough.
2)Onceyougetintoabadhabit,you'llfindithardtogetoutofit.
Twice代表两次,两倍
--副词Adverb
1)Hecomestoworktwiceaweek.
2)Thedining-roomistwiceasbigasthekitchen.