This exercise contains a number of key features demonstrating the version 7 JMatch enhancements. It has the following complex features:

• Multiple instances of the same category on the left, with multiple instances of words that can match with each instance of some of those categories.
• Multiple instances of the same word on the right, where each can match with a different category (smell = noun, smell = verb).
• Distractors on the left for which there are no matches on the right.
• Distractors on the right, for which there are no matching categories on the left.
• Shuffling of the left items as well as the right items.
• A configured setting to show a limited number of items every time the page loads, so some must be discarded from each side.
• A reading text.
• A timer.

This is how the exercise works:

• It ensures that any randomly-reduced selection of items has at least one correct configuration that can be accomplished.
• It marks each individual answer correct according to whether it is a good match or not, but also marks the exercise according to whether all the matches are correct or not.
• It retains the positions of already-matched items whenever the window is resized, including cases of bad matches which have been marked by checking the answers.