英译汉

Unlike a film, __________  a passive audience watches and hears __________  is happening on the screen, Real Cine puts you into the action and connects with your senses of sight, smell and touch in an active way.

在$△ABC$中，A=$\frac{3\mathrm{\pi }}{4}$,AB=6，AC=3$\sqrt{2}$,点D在BC边上，AD=BD，求AD的长