Combine mandarin oranges, grapefruit sections, and lettuce in a large salad bowl; toss lightly. Serve with Poppy Seed Dressing. Poppy Seed Dressing: Combine first 7 ingredients in container of electric blender; blend well. Slowly add 3/4 cup vegetable oil, continuing to blend until thick. Pour into a jar with a tight-fitting lid, and chill. Shake well before serving. Yield: 2 cups Food Exchange per serving: 1 FRUIT EXCHANGE + 1 FAT EXCHANGE SOURCE: Southern Living Magazine, July, 1980. Typed for you by Nancy Coleman. Nancy O'Brion's Notes: Would for sure use less OIL!