获取：42 http://cn.archive.ubuntu.com precise-backports/main Sources [743 B]   
100% [42 Sources xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别
获取：43 http://cn.archive.ubuntu.com precise-backports/restricted Sources [743 B]
100% [43 Sources xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别
获取：44 http://cn.archive.ubuntu.com precise-backports/universe Sources [743 B]
100% [44 Sources xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别
100% [19 Sources xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别 
获取：45 http://cn.archive.ubuntu.com precise-backports/universe i386 Packages [743 B]
100% [45 Packages xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别
获取：46 http://cn.archive.ubuntu.com precise-backports/main Translation-en [743 B]
100% [46 Translation-en bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：47 http://cn.archive.ubuntu.com precise-backports/multiverse Translation-en_US [743 B]
100% [47 Translation-en_US bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：48 http://cn.archive.ubuntu.com precise-backports/multiverse Translation-en [743 B]
100% [48 Translation-en bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：49 http://cn.archive.ubuntu.com precise-backports/restricted Translation-zh_CN [743 B]
100% [49 Translation-zh_CN bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：50 http://cn.archive.ubuntu.com precise-backports/restricted Translation-zh [743 B]
100% [50 Translation-zh bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：51 http://cn.archive.ubuntu.com precise-backports/restricted Translation-en_US [743 B]
100% [51 Translation-en_US bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：52 http://cn.archive.ubuntu.com precise-backports/restricted Translation-en [743 B]
100% [52 Translation-en bzip2 0 B] [正在等待报头]            831 B/s 0秒bzip2: (stdin) is not a bzip2 file.
获取：53 http://cn.archive.ubuntu.com precise-backports/universe Translation-zh_CN [743 B]
100% [53 Translation-zh_CN bzip2 0 B] [正在等待报头]         118 B/s 6秒bzip2: (stdin) is not a bzip2 file.
获取：54 http://cn.archive.ubuntu.com precise-backports/universe Translation-zh [743 B]
100% [54 Translation-zh bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：55 http://cn.archive.ubuntu.com precise-backports/universe Translation-en_US [743 B]
100% [55 Translation-en_US bzip2 0 B] [正在等待报头]bzip2: (stdin) is not a bzip2 file.
获取：56 http://cn.archive.ubuntu.com precise-backports/universe Translation-en [13.8 kB]
获取：57 http://cn.archive.ubuntu.com precise-security/main Sources [743 B]
100% [57 Sources xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别
获取：58 http://cn.archive.ubuntu.com precise-security/multiverse Translation-zh [102 kB]
获取：59 http://cn.archive.ubuntu.com precise/main i386 Packages [36.5 kB]
100% [59 Packages lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [36 Translation-en_US xz 0 B] [正在等待报头]/usr/bin/xz: (stdin): 文件格式无法识别
获取：60 http://cn.archive.ubuntu.com precise/main Translation-zh_CN [743 B]
100% [60 Translation-zh_CN lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：61 http://cn.archive.ubuntu.com precise/restricted Translation-zh [743 B]
100% [61 Translation-zh lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：62 http://cn.archive.ubuntu.com precise/restricted Translation-en_US [743 B]
100% [62 Translation-en_US lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：63 http://cn.archive.ubuntu.com precise/restricted Translation-en [743 B]
100% [63 Translation-en lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：64 http://cn.archive.ubuntu.com precise/universe Translation-zh_CN [743 B]
100% [64 Translation-zh_CN lzma 0 B] [正在等待报头]        24.9 kB/s 0秒/usr/bin/lzma: (stdin): 文件格式无法识别
获取：65 http://cn.archive.ubuntu.com precise/universe Translation-zh [743 B] 
100% [65 Translation-zh lzma 0 B] [正在等待报头]           24.9 kB/s 0秒/usr/bin/lzma: (stdin): 文件格式无法识别
100% [26 Translation-zh_CN lzma 0 B] [正在等待报头]          118 B/s 6秒/usr/bin/lzma: (stdin): 文件格式无法识别
100% [27 Translation-en_US lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [28 Translation-en lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：66 http://cn.archive.ubuntu.com precise-backports/main i386 Packages [743 B]
获取：67 http://cn.archive.ubuntu.com precise-backports/restricted i386 Packages [743 B]
100% [46 Translation-en lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：68 http://cn.archive.ubuntu.com precise-backports/multiverse Translation-zh_CN [743 B]
100% [68 Translation-zh_CN lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [49 Translation-zh_CN lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [52 Translation-en lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [53 Translation-zh_CN lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [54 Translation-zh lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
100% [55 Translation-en_US lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：69 http://cn.archive.ubuntu.com precise-security/restricted Sources [743 B]
获取：70 http://cn.archive.ubuntu.com precise-security/universe Sources [743 B]
获取：71 http://cn.archive.ubuntu.com precise-security/multiverse Sources [743 B]
获取：72 http://cn.archive.ubuntu.com precise-security/main i386 Packages [743 B]
获取：73 http://cn.archive.ubuntu.com precise-security/main Translation-en [743 B]
100% [73 Translation-en lzma 0 B] [正在等待报头]             121 B/s 6秒/usr/bin/lzma: (stdin): 文件格式无法识别
获取：74 http://cn.archive.ubuntu.com precise-security/multiverse Translation-zh_CN [743 B]
100% [74 Translation-zh_CN lzma 0 B] [正在等待报头]          121 B/s 6秒/usr/bin/lzma: (stdin): 文件格式无法识别
获取：75 http://cn.archive.ubuntu.com precise-security/multiverse Translation-en_US [743 B]
100% [75 Translation-en_US lzma 0 B] [正在等待报头]          121 B/s 6秒/usr/bin/lzma: (stdin): 文件格式无法识别
获取：76 http://cn.archive.ubuntu.com precise-security/multiverse Translation-en [743 B]
100% [76 Translation-en lzma 0 B] [正在等待报头]             121 B/s 6秒/usr/bin/lzma: (stdin): 文件格式无法识别
获取：77 http://cn.archive.ubuntu.com precise-security/restricted Translation-zh_CN [743 B]
100% [77 Translation-zh_CN lzma 0 B] [正在等待报头]          121 B/s 6秒/usr/bin/lzma: (stdin): 文件格式无法识别
获取：78 http://cn.archive.ubuntu.com precise-security/restricted Translation-zh [743 B]
100% [78 Translation-zh lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：79 http://cn.archive.ubuntu.com precise-security/restricted Translation-en_US [743 B]
100% [79 Translation-en_US lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：80 http://cn.archive.ubuntu.com precise-security/restricted Translation-en [743 B]
100% [80 Translation-en lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：81 http://cn.archive.ubuntu.com precise-security/universe Translation-zh [743 B]
100% [81 Translation-zh lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：82 http://cn.archive.ubuntu.com precise-security/universe Translation-en_US [743 B]
100% [82 Translation-en_US lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别
获取：83 http://cn.archive.ubuntu.com precise-security/universe Translation-en [743 B]
100% [83 Translation-en lzma 0 B] [正在等待报头]/usr/bin/lzma: (stdin): 文件格式无法识别

sudo apt-get update