Create a question like Q2 in http://school.demo.moodle.net/mod/quiz/view.php?id=761
Preview it.
Ensure that the size of the pop-up it such that the boxes on neighbouring lines are vertically one above another.
Verify that the boxes don't touch.
Put some drag items in some of the boxes.
Verify that the baseline of the text in the drag item lines up with the baseline of the surrounding text.