Marinated Cucumbers, Onions, and Tomatoes

3 medium cucumbers, peeled and sliced 1/4 inch thick

1 medium onion, sliced and separated into rings

3 medium tomatoes, cut into wedges

1/2 cup vinegar

1/4 cup sugar

1 cup water

2 teaspoons salt

1 teaspoon fresh coarse ground black pepper

1/4 cup oil

Combine ingredients in a large bowl and mix well.