她向我们出示护照作为身份证明。

She showed us her passport as ___proof of her identity.

他们有证据证明是汉普森偷了货物吗？

Do they have any ___proof that it was Hampson who stole the goods?

孩子的微笑是动物园效用的最佳证明。

The smile of a child is the best ___proof of the utility of zoos.