关于x的方程x2-2x+k=0有两个不相等的实数根,则k的取值范围是[ ]
A.k<1
B.k>1
C.k<-1
D.k>-1
答案:A
负债的定义是什么,确认条件有哪些?
Beijing: The United States and North Korea had their first ______ in four months here this afternoon as part of the ______ negotiations on how to end North Korea’s nuclear program, but diplomats played down prospects for______. James A. Kelly, assistant ______, and Kim Yong Ⅱ, North Korea’s deputy foreign minister, met ______ of formal discussions, ______ on direct dialogue that began after a stormy meeting ______ in which North Korea warned that it was moving quickly to ______ nuclear arms. The Bush administration had insisted ______ that it would only hold talks with North Korea ______ because, it argued, only ______ pressure would persuade North Korea to______. It got its way when North Korea dropped its insistence on ______ and agreed, after extensive efforts by China, to hold unusual simultaneous negotiations with ______,______,______ and ______ as well as the United States. Though Bush administration officials had not ______ talking privately with the North Koreans during______, the fact that Mr. Kelly and Mr. Kim met on the first day was seen as a sign of ______ by the American side.