How to make mushroom barley soup<br>Chop the vegetables. Wash 1 pound (480 g) of mushrooms , 2 large carrots , 2 large celery stalks, and peel 1 onion. Use a sharp knife to carefully cut the mushrooms into 1/2-inch (12 mm) pieces.
you need to wash the mushrooms. 
( z1 need :ARG0 ( z2 you ) :ARG1 ( z3 wash :ARG0 z2 :ARG1 ( z4 mushroom ) ) )