W250511/10-vuecli/vueapp/myappthree/src/main.js

import Vue from 'vue'
import ElementUI from 'element-ui';
import 'element-ui/lib/theme-chalk/index.css';
import App from './App.vue'

Vue.config.productionTip = false
Vue.use(ElementUI);
new Vue({
  render: h => h(App),
}).$mount('#app')