要么因为信用证金额太大，要么因为对开证行不完全信任，出口商有时可能需要保兑信 用证。

要么因为信用证金额太大，要么因为对开证行不完全信任，出口商有时可能需要保兑信 用证。
【正确答案】：Either because the credit amount is too large, or because he does not fully trust the opening bank, the exporter may sometimes require a confirmed letter of credit.