make practical jokes由问题和答案的其他部分可知这里需要填入动词短语。根据听力原文中的第一句Americans like to laugh and make practical jokes，which are indeed to tric

Americans like to laugh and make practical jokes, which are intended to trick or deceive people in some harmless way. April Fools Day, the first day in April, is a day devoted to such jokes and an excuse for every American to fool his friends and neighbors. When I was a college student, our daily college newspaper always had a special edition. One year the paper said that a beautiful park in the center of the campus was to be turned into a parking lot. It was surprising that many people believed these stories. But probably the most successful practical joke was a national radio broadcast by Orson Wells. Mr. Wells told his audience that the Earth was being invaded by Mars. His description of this invasion from outer space was so realistic that he caused a panic and was actually responsible for the death of several people.