As you only have a short stay in Shanghai, you probably will not be able to do much more sightseeing. But if I can help in any other way, please let me know.

由于您在上海只能做短暂停留，您可能无法做太多的观光。但如果我能在任何其它方面帮上您的忙，敬请告知我。

youdao

If you do please let me know.

如果您这样做了请告之我。

youdao

Please let me off here.How much do I owe you?

请让我在这里下车。我该付你多少钱？

youdao

If you have this uncanny ability please do let me know.

BBC: Clive Stuart-Smith column

"If in fact you do make contact with Martians, please let me know right away, " he said, receiving more laughter.

CNN: Mars rover mission's 'Mohawk Guy' inspires Obama