A:x≥0
B:x <0且x≠l
C:x<0
D:x≥0且x≠l
有人认为19世纪是人类科学发展史上的辉煌时代。下列不属于这一时代的科学成果是( )
等腰三角形的腰为13cm,底边长为10cm,则它的面积为____ cm2
— The earthquake in Wenchuan in 2008 killed people.
— We were sad to hear that.