aligning all input fields perfectly - css

Question

I want to align all the input fields in a single line inside a table.
Currently I have 3 input fields and 2 select fields in a table. They are getting displayed like this
I want all that input fields in a same straight line.
Both the select fields looks like they have top margin but I didn't use any margin properties on that.
That's the code which I have used to display this.
<div class="content">
<div class="white-bg md-whiteframe-4dp">
<table class="dataTable row-border hover" datatable="ng" dt-options="vm.dtOptions">
<thead>
<tr>
<th class="secondary-text">
<div class="table-header">
<span class="column-title">S.No.</span>
</div>
</th>
<th class="secondary-text">
<div class="table-header">
<span class="column-title">Material Group</span>
</div>
</th>
<th class="secondary-text">
<div class="table-header">
<span class="column-title">Estimated Quantity</span>
</div>
</th>
<th class="secondary-text">
<div class="table-header">
<span class="column-title">Discount Rate</span>
</div>
</th>
<th class="secondary-text">
<div class="table-header">
<span class="column-title">Currency</span>
</div>
</th>
<th class="secondary-text">
<div class="table-header">
<span class="column-title">Total Discount</span>
</div>
</th>
</tr>
</thead>
<tbody>
<tr ng-repeat="row in ::vm.tableData">
<td>
{{row.id}}
</td>
<td>
<md-input-container class="md-block">
<md-select ng-model="row.materialGroupName" placeholder="Weapon">
<md-option value="null" selected disabled>Material Group Name</md-option>
<md-option value="group1">Group 1</md-option>
<md-option value="group2">Group 2</md-option>
<md-option value="group3">Group 3</md-option>
</md-select>
</md-input-container>
</td>
<td>
<md-input-container class="md-block">
<input type="number" ng-model="row.quantity">
</md-input-container>
</td>
<td>
<md-input-container class="md-block">
<input type="number" ng-model="row.discountRate">
</md-input-container>
</td>
<td>
<md-input-container>
<md-select class="md-block" ng-model="row.currency">
<md-option value="null" selected disabled>Select Currency</md-option>
<md-option value="inr">INR</md-option>
<md-option value="usd">USD</md-option>
<md-option value="gbp">GBP</md-option>
</md-select>
</md-input-container>
</td>
<td>
<md-input-container class="md-block">
<input type="number" ng-model="row.total">
</md-input-container>
</td>
</tr>
</tbody>
</table>
</div>
</div>
I've also tried to remove the margin which md-input-container brings with him but that didn't work for me.