2017-4-7 更新：我前几天重新安装了一下系统，下载是最新版本的ubuntu16.04,发现没有遇到找不到wifi和无声音的问题。如果你遇到了此问题，换一个最新的系统安装试试，不行的话再按下面的方法解决

1.找不到wifi

You can install a better driver(安装一个更好的驱动，这个驱动好像也通用)

sudo add-apt-repository ppa:hanipouspilot/rtlwifi
sudo apt-get update
sudo apt-get install rtlwifi-new-dkms linux-firmware

And reboot（重启）

2.无声音

After searching,I have found a simple answer. Just execute

killall pulseaudio
Your speakers should work fine now. To ensure this,test the sound stack in System Settings > Sound > Test Sound (Speaker test,Not Digital Output (S/PDIF) test)

The only problem with your issue is there is no driver found for your audio for that then Try to reinstall pulse audio and Alsa,open terminal and enter the following commands-

sudo apt-get remove --purge alsa-base pulseaudio
sudo apt-get install alsa-base pulseaudio
sudo alsa force-reload

even Upgrading your sound drivers may fix the nosound issue,for that use the following commands -

sudo add-apt-repository ppa:ubuntu-audio-dev
sudo apt-get update
sudo apt-get dist-upgrade

the final try from me is to make some changes in speech-dispather by-

sudo gedit /etc/default/speech-dispatcher

and change

RUN=yes
to

RUN=no
hope these workarounds will solve your issue,before testing make sure to restart once after doing any of the method.

3.遇到的问题

会遇到

The sounds options disappear completely from my Ubuntu
声音面板会从Ubuntu的工具栏中消失

解决办法：在终端输入命令sudo apt-get install ubuntu-desktop,然后重启即可恢复。