Mark the sentences T (true), F (false) or NS (not stated). 1 April Fool's Day is only celebrated in English-speaking countries. 2 One theory about the origin of April Fool's Day suggests that it started due to a change in the calendar. 3 There is only one traditional way to make someone a Fool. 4 April Fool's Day can be celebrated for two days. 5 It's important to make sure that jokes on April Fool's Day are kind and fun for everyone involved.