Old Fashioned Biscuits

2 cups flour
2 tsp baking powder
1 tsp salt
1/4 tsp soda
2 Tbsp shortening
3/4 cup sour milk

Sift together flour, baking powder, salt and soda. Blend in shortening. Add sour milk and work lightly. Cut into desired shape. Put on a lightly greased pan and bake until brown in a hot to medium oven.