如何将ng select转换为md-select

Question

我有ng-select

的旧代码

<ng-select
    [active]="cntry"
    [items]="countryList"
    (data)="refreshCountryValue($event)"
    placeholder="{{ezzy.LOCALIZATION.cntry}}"></ng-select>

我想将其转换为md-select

<md-select placeholder="Country" >
   <md-option></md-option>
</md-select>

我该怎么做？