Can direct coupled amplifier amplify AC signal? Why?

Can direct coupled amplifier amplify AC signal? Why?

Of course! Capacitors are added between all levels of the amplifying circuit to isolate DC signals. That's because only AC signals are useful signals and DC signals are useless signals (such as audio and video signals in radio and TV sets). In order to amplify useful AC signals better, the working point of amplifying circuits at all levels must be stable at