单项选择题 （） in the United States（）.

单项选择题 School integration plans that involve busing between suburban and central-city areas have contributed, according to a recent study, to （） any future need/or busing.

单项选择题 The economic forces which may affect the new public offering of stock include sudden downturns in the market, hedging and other investor strategies for preventing losses,（） the interest rates in Washington, and （） undercapitalized.