Translating list with checkboxes, to a combo of dropdowns

1. How do I select multiple options from a drop down list in a checkbox?

How do I select multiple options from a drop down list in a checkbox?

But in this case, multiple options can be selected by holding down the control (ctrl) button of the keyboard. Instead of using the multiple attributes in HTML, you can use jQuery to make the multi-select dropdown more user-friendly and add the checkbox to each option in the multi-select dropdown.