Operator script (click here to toggle)

Every one second, the document alternates between two states. In the first state, the top circle shows the number "02", the bottom circle shows "03", the two images show a picture of the Sydney Opera House, and the two 'use' elements show the text "Use A". In the second state, the top circle shows the number "38", the bottom circle shows "09", the two images show a picture of some water and land, and the two 'use' elements show the text "Use B".

The test passes if the document does alternate between these two states, and that clicking on the circles produces the behavior described in the operator script.