她如此快速地解决复杂问题的能力是天才的标志。

Her ability to solve complex problems so quickly is ___a ___mark ___of genius.

各处默哀一分钟以示敬意。

There was a minute's silence everywhere as ___a ___mark ___of respect.

完成马拉松是他决心的标志。

Completing the marathon was ___a ___mark ___of his determination.