1929年大崩盘，经济崩溃，悲剧频现。often后面动词什么形式

　　A documentary exploring the causes of the 1929 Wall Street Crash. 　　Over six terrifying, desperate days in October 1929, shares crashed by a third on the New York Stock Exchange. More than $25 billion in individual wealth was lost. Later, three thousand banks failed, taking people's savings with them. Surviving eyewitnesses describe the biggest financial catastrophe in history. 　　I... (展开全部)