a bright red flag的用法和样例：
- A bright red welt rose on his arm.
- A bright red mercuric sulfide used as a pigment.
- He takes off his coat to reveal a bright red vest.
- The leaves were tinctured with a bright red.
- It's easy to recognize the girl even she is set among a group of girls because she wears a bright red hair.
- While we waited, we saw a bright red fire shooting to the sky.