To get the value of select using ng-modle, or can not get the value of select

ng-bind scope from $ -> View of the way binding 
ng -modle is $ scope <-> view of the two-way binding

                    <form role="form" class="form-inline">
                    
                        <div class="form-group">
                            <label for="nj">年级:</label>
                            <select name="nj" id="nj" class="form-control"  ng-model="myNJ">>
                                <option ng-repeat="op in njs " value="{{op.id}}">{{op.name}}</option>
                            </select>
                       </div>
                       
                        <div class="form-group">
                            <label for="zy">年级:</label>
                            <select name="zy" id="zy" class="form-control"  ng-model="myZY">
                                <option ng-repeat="op in zys " value="{{op.id}}">{{op.name}}</option>
                            </select>
                        </div>
                        
                       <button type="submit"  class="btn btn-primary" id="chaxun" ng-click="fn1()" >查询</button>
                       
                    </form>