解:原式=﹣a3b﹣2a2b2﹣5a3b+5a2b2
=﹣6a3b+3a2b2.
On April 25th,2007,thousands of Russians went to say farewell to Boris Yeltsin—the country's first popularly ________leader.
某同学选择的研究主题是***关于“工农武装割据”的理论。他可查阅的历史资料是
据此,请回答以下几个问题。