typePeople struct{}
func(p *People) ShowA() {
    fmt.Println("showA")
    p.ShowB()
}
func(p *People) ShowB() {
    fmt.Println("showB")
}
typeTeacher struct{
    P People
}
func(t *Teacher) ShowB() {
    fmt.Println("teacher showB")
}
funcmain() {
    t := Teacher{}
    t.ShowA()        //报错
    t.People.ShowA() //报错
    t.People.ShowB() //报错
    t.ShowA()       // 报错
    t.ShowB()   //teacher showB
    t.P.ShowA() //showA\nshowB
    t.P.ShowB() //showB
}