zài / huòwù / zhuāngyùn / qián / màifāng / bìxū / jíshí / cuīzhèng / yǐmiǎn / yánwù / chuánqī在货物装运前,卖方必须及时催证,以免延误船期。Before shipment, the seller must promptly call for the L/C to avoid delaying the shipping schedule.