In many countries, a driving license is a valid proof of identity.

驾驶执照在很多国家是有效的身份证明。

I renewed my passport, my proof of identity as a Canadian citizen. I knew that once I arrived in China I would also be registered with the Canadian Embassy.

我延长了护照的期限，那是确认我是一个加拿大公民的证明。一旦抵达中国，我还要在加拿大使馆登记。