Lu people emigrated to Vietnam. There is a man in Lu who knows how to knit and his wife knows how to spin white silk. The couple want to move to Vietnam. Someone said to him, "If you go to Vietnam, you will definitely become poor." Lu asked, "Why?" The man replied, "shoes are for people to wear, but Vietnamese people are used to walking barefoot;" Woven white silk is used to make hats, but Vietnamese people like to let their hair hang freely without hats. With your expertise, you can go to a country that doesn't need you. What can I do if I don't want to be poor? Lu asked him, "We can guide them to wear shoes and hats where we don't need our expertise. With the continuous promotion of uses, how can we be poor? "