I do solemnly promise and declare that I would not open or delay or cause to be forced to ope or delay any letter or anything by posed.

我庄严地承诺绝不擅自打开或延迟，或者在逼迫下打开或延迟任何信件或邮寄的物品。

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I do solemnly promise and declare that I will not open, or delay, or cause or suffer to be opened or delayed, any letter or anything sent by post.

我庄严承诺并且宣誓，我不会擅自打开或延误，或致使别人或被迫去打开或者延误任何信件，或者任何其它邮寄来的邮件。

youdao

I do solemnly, sincerely and truly declare that all the information given herein is true.

本人谨郑重至诚据实声明∶此申请书所载各项均属真实。

youdao

"I, Julia Eileen Gillard, do solemnly and sincerely affirm and declare that I will loyally serve the Commonwealth of Australia in the office of prime minister, " she said in the ceremony in the Australian capital, Canberra.

BBC: Gillard sworn in as Australian prime minister