他用一封介绍信作为身份的证明。

He used a letter of introduction as identification.

youdao

若本合同遗失，可凭单位介绍信及联系人个人身份证复印件或代理人身份证复印件领取。

If they missed the contract, they can take the introduction letter of the unit or the photocopy of contract person's ID or agency person's ID instead of.

youdao

委托方自取，可凭本协议书或单位介绍信、联系人身份证复印件等其他有效凭证领取。

If they missed the contract, they can take the introduction letter of the unit or the photocopy of contract person's ID or other credit to take the test report.

youdao

委托方自取，可凭本协议书或单位介绍信、联系人身份证复印件等其他有效凭证领取。

If they missed the contract, they can take the introduction letter of the unit or the photocopy of contract person's ID or other credit to take the test report.

youdao