try ...on 的用法

This pair of shoes is new,can I try them on?主语是this pair 应该用单数.后面试穿两只shoes用them.
至于This pair of glasses is new,can I try them on?还有pants等这类词还是用them.
This bowl of rice is mine.
全部用单数.
如果量词是复数,当然谓语用复数.
These two pairs of shoes are new,can I try them on?