I certify this as a true copy of his letter.

我证明本件确系他信件的副本。

youdao

I certify this as a true copy of his letter.

兹证明本件确系他信件的副本。

youdao

I certify that this is a true copy.

我证明这是真副本。

youdao

I certify that this is a true copy.

我证明这是真副本。

youdao