function createLight(){
    //work 1
}
function createEarth(){
    //work 2
}
function createPlants(){
    //work 3
}
function createAnimals(){
    //work 3
}

function createWorld(){
    createLight()
    createEarth()
    createPlants()
    createAnimals()
}

function createWorld(){
    //create light
    //work1
    createEarth()
}
function createEarth(){
    //work 2
    createPlants()
}
function createPlants(){
    //work 3
    createAnimals()
}
function createAnimals(){
    //work 4
}