常見例句雙語例句Rechargeable lithium ion battery power – charges by connecting to your USB port or using the optional Flip Video Power Adapter (sold separately).充電式鋰離子電池電源-費由連接到您的U SB連接埠或使用可選的倒裝眡頻電源適配器（單獨出售） 。權(quán)威例句Part D is an optional insurance program that charges a monthly fee in exchange for prescription drug coverage.FORBES: The ABCDs of MedicareThe company charges for providing the optional financial adviser.FORBES: Personal Capital Launches Financial Adviser Service From Former Intuit CEO 返回 optional charges