基本解释[经济学]光单信用证英汉例句双语例句Clean letters of credit are mainly used in non-trade settlement, while documentary credits are generally used in commodity trade.光票信用证主要用于非贸易结算，而在商品贸易中一般使用跟单信用证付款。documentary clean credit更多例句专业释义经济学光单信用证