I have array of strings and I want to place every two of them in a row with ngFor. Here is what I tried:

```
<div class='row wow fadeInUp' *ngFor='let index of myArray;let i = index;'>
     <div class='col-md-6'>
         <md-card>
            <md-card-header>
               <md-card-title>
                 {{index}}
               </md-card-title>
             </md-card-header>
          </md-card>
     </div>
     <div class='col-md-6' *ngIf='i+1 < myArray.length'>
         <md-card>
            <md-card-header>
               <md-card-title>
                 {{myArray[i+1}}
               </md-card-title>
             </md-card-header>
          </md-card>
    </div>
</div>

```

But when I add a new element, it duplicates the previous element and I really don't underestand the reason. How can I add two elements in each row with ngFor?