Zucchini Chocolate Cake
["1/4 c. margarine", "1/4 c. shortening", "1/2 c. vegetable oil", "1 1/2 c. sugar", "1 egg", "1 tsp. vanilla", "1/2 c. sour milk*", "2 1/2 c. flour", "4 tsp. baking soda", "2 c. zucchini", "1 Tbsp. cocoa", "2 tsp. orange rind"]
["*To sour milk, add 1/2 teaspoon vinegar."]
["margarine", "shortening", "vegetable oil", "sugar", "egg", "vanilla", "sour milk", "flour", "baking soda", "zucchini", "cocoa", "orange rind"]