How time flies!Ten years --- (pass) since I met you last time.

问题描述:

How time flies!Ten years --- (pass) since I met you last time.

has passed
since I met you last time。since引导的状语从句是主句选择选现在完成时的经典标志

has passed
since提示用完成时
10年作为一个整体,做单数,用has