仅当getJSON花费超过n毫秒时才显示元素?

I have some JavaScript:

我有一些JavaScript:

surveyBusy.show();

$.getJSON(apiUrl + '/' + id)
    .done(function (data) {
        ...
        surveyBusy.hide();
    })
    .fail(function (jqXHR, textStatus, err) {
        ...
        surveyBusy.hide();
    });
sur