The abnormal bleeding is your body's own red flag of danger.

这反常的流血是你身体本身的危险信号。

Then the rain came and the red flag went up to signal a halt.

当时，雨下了起来，红旗被升起，发出停止的信号。

A red flag rose up before the building.

一面红旗从大楼前升了起来。

The red flag fell.

那面红旗倒了。

The five-star red flag was inserted into the summit of Mount Everest.

五星红旗插上了珠穆朗玛峰的顶峰。