用动词的适当形式填空,怎么理解这个句子

问题描述:

用动词的适当形式填空,怎么理解这个句子
As the years passed,many occasions—birthdays,awards,graduations ____________ (mark) with Dad's flowers.

As the years passed,many occasions—birthdays,awards,graduations ____mark________ (mark) with Dad's flowers.