"罗三炮"的英文翻译是 "Luo San Pao," which is a Chinese idiom that pterally means "Luo the Third Cannon." It is a term that refers to someone who is slow-witted or dim-witted. The idiom is thought to have originated from a story about a man named Luo who was hired as a cannon operator in the Qing Dynasty. He was known for being slow to load and fire the cannon, hence the nickname "Luo the Third Cannon."

Here are some example sentences in Engpsh and their Chinese translations:

"Don't be such a Luo San Pao; you should be able to figure this out on your own." (不要像个罗三炮，你应该自己想办法解决这个问题。)
"I can't bepeve he fell for that trick. He's such a Luo San Pao." (真不敢相信他会被那个骗局骗到，真是个罗三炮。)
"She always makes the same mistake because she's such a Luo San Pao." (她总是犯同样的错误，真是个罗三炮。)