"Gifts must be given" 可以用英文表达为 "Gifts must be presented" 或 "Gifts must be bestowed upon." 这个短语的来源可能源于英语中给予礼物的惯例。

下面是一些例句:

"According to tradition, gifts must be presented on the wedding day." (按照传统,礼物必须在婚礼当天送出。)
"As a sign of respect, gifts must be bestowed upon the host when visiting their home." (作为尊重的表示,拜访别人家时必须送礼物。)
"In some cultures, it is customary for guests to bring gifts when attending a party or event." (在一些文化中,客人参加聚会或活动时送礼物是惯例。)

希望这些例句能帮助你理解 "gifts must be given" 这个短语的意思。