A．cleannessB．multi-ethnicityC．modem characteristicsD．sh……

填空题改because为because of。

填空题改Because为Though或Although。

填空题content essentials

填空题改suburban为rural。

单项选择题A．US Defense secretary Donald RumsfeldB．US Federal Reserve chairman Alan GreenspanC．US President George W. BushD．US Vice President Dick Cheney