A:28°,120°
B:120°,28°
C:32°,120°
D:120°,32°
已知f(x)dx=56,则( )
据史书记载:“清朝乾隆、嘉庆时期,徽商经营达到极盛,然而从道光、咸丰时期至清末民初,徽商渐趋衰落。”对此理解不正确的是
①2:7 ②5:4 ③4:5 ④7:2.
His family__________ all very kind and friendly. His family__________ a happy one.