单项选择题
A. diverse B. durable C. epidemic D. drastic
A. Life of famous African Americans B. Influence of famous African Americans C. Political pioneers: Icons and intellectuals D. Cultural pioneers: Icons and intellectuals
A. buy more shares when the stock price falls down B. sell out the shares when the stock price falls down C. do some research on the value of a business when its stock price falls down D. invest in the business when its stock price falls down