执行apt-get install xxxx时，报以下错误
E: There are problems and -y was used without --force-yes
解决方案：
vim /etc/apt/sources.list
删除原有，添加如下：
deb http://old-releases.ubuntu.com/ubuntu/ natty main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-security main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-updates main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-proposed main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-security main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-updates main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-proposed main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ natty-backports main restricted universe multiverse
注意：这里使用的是ubuntu的源，也可以网上找源去，不过bt系列的源已经停止更新了，部分软件已经找不到了
kali可以添加以下源：
deb http://mirrors.ustc.edu.cn/kali kali-rolling main non-free contrib
deb-src http://mirrors.ustc.edu.cn/kali kali-rolling main non-free contrib
替换源
apt-get update
如果把源改了以后，在bt5上执行apt-get install xxx时报以下错误
E: Sub-process /usr/bin/dpkg returned an error code (1)
处理方法：
mv /var/lib/dpkg/info /var/lib/dpkg/info.bak //现将info文件夹更名
mkdir /var/lib/dpkg/info //再新建一个新的info文件夹
apt-get update
apt-get -f install
mv /var/lib/dpkg/info/* /var/lib/dpkg/info.bak
rm -rf /var/lib/dpkg/info //把自己新建的info文件夹删掉
mv /var/lib/dpkg/info.bak /var/lib/dpkg/info //把以前的info文件夹重新改回名字
apt-get update
最后：bt系列的源不再更新了，上述方法可能不能够完全解决你的问题，建议用kali去做任务