dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem. E: _cache->open() failed, please report.
上网搜索了一下中文网站，里边没有能解决问题的，于是上了ubuntu国外论坛，在里面搜索，终于解决问题了：
代码如下：
sudo dpkg --configure -a
Enter your password when prompted. Then try
sudo apt-get update followed by sudo apt-get upgrade
If you've already tried this or you try it now and it isn't working then post the full output from apt-get here.
What package was being installed when apt-get failed? You should be able
to see this in the output just prior to the error message you've shown.
详细地址：http://ubuntuforums.org/showthread.php?t=388348
最后又在终端出现了这样的一个问题：、
libc6-dev:依赖:libc6(=2.9-4ubuntu6.1) 但是2.9-Ubuntu6已经安装了 E：不能满足依赖关系。不妨试一下-f选项 于是我在终端输入sudo apt-get -f install
问题得到解决！