题目

________ as one, the people of that country eventually drove the invaders (侵略者)out of their country.        A. Linked              B. Combined      C. Joined              D. United 答案：D 某烃与溴水反应生成物为2,2,3,3－四溴丁烷，则该烃的同分异构体是(　　) A．1－丁炔                              B．2－丁炔 C．1－丁烯                              D．1,3－丁二烯