This quiz is in the form of a true story in question and answer form, and focuses on the regular past and the past continuous. It is a strange story:
A Japanese man, Mr. Katougoru, was standing in a crowded train when, suddenly, his underwear attacked the other passengers in the train. Fortunately, one of the passengers fought back and no one was hurt. Later, an embarrassed Mr. Katougoru explained that it happened because he was afraid of drowning.

To know the situation and to understand how the quiz works, click  here.