微笑是北京最好的一张名片。怎么翻译？

Smiling is the most fantastic postcard of Beijing,
smiling can transport the friendship and the passion to everybody,so smiling is the most fantastic postcard of Beijing.

Smile is Beijing's best calling card.
Smile conveys passion and friendship among people, it is the best calling card of Beijing.

名片千万不能翻成name card.

Smiles let people exchange their passions and friendship. They are the best namecards of Beijing.

Smile conveys the zealousness and friendship among people.It's the best namecard/calling care/visiting card of Beijing.

Smile is the mark of Beijing city.

Smile show the passion and friendship among people, it's the best qualified mark of Beijing city.

The best card of Beijing is smile
Smile transports the zealousness and friendship amone people,which is the best card of Beijing