Why are facial expressions so important when signing in asl?

I'm not exactly sure but it can be used to reveal the emotion and how the person feels about a certain situation

1one sharp difficulty presented itself. in the intervening twenty-five years my name had become reasonably well known.2 this being so, my trip demanded that i leave my name and my identity at home.3 i had to go alone and i had to be self-contained, a kind of casual turtle carrying his house on his back.4 with all this in mind i wrote to the head office of a great corporation which manufactures trucks.

We need the profession and injuries