Once opened, this product should be kept refrigerated.

本产品开封后应冷藏。

《牛津词典》

Once opened, the XML file is mapped into tabular structure.

这个 XML 文件被打开后，就会被映射到表结构中。

youdao

The past surged up before him facing the present; he compared them and sobbed. The silence of tears once opened, the despairing man writhed.

过去又回来和现在正面相对；他比较了一下，于是嚎啕痛哭，眼泪的闸门一开，这个失望的人便哭得直不起腰来。

youdao

There is a wine that once opened, will still taste fresh and fabulous decades later.

FORBES: Why Madeira Is The Next Great Thing In Wine

Once opened it forwards itself using the personal and business address books of e-mails so the spread is rapid.

BBC: You are in: UK

And once we opened the court up, we could get into the lane and make plays and fire up shots.

NPR: Thunder Holds Off Clippers To Win 108-104