这栋大楼顶上的旗帜很高 。

The ___flag on top of this building is very high.

老师用红色笔标记出作业中的错误。

The teacher ___flagged the mistakes in the homework with a red pen.

到了下午三点，他的注意力开始不集中了。

By 3 PM, his concentration began to ___flag.

奥运会上，运动员们高举各自国家的旗帜入场。

At the Olympics, athletes carry their country's ___flag during the opening ceremony.