In case you lose your keys, keep a set of duplicates somewhere safe.为防钥匙丢失，配一套放在安全地方备用。If there are duplicates of some ingredient, they'll simply try different dishes.如果配料有重复的话，他们就会尝试不同的菜肴。He made duplicates of the forms before mailing them.他在邮寄这些表格之前复印了几份。