a dab of rouge的用法和样例：
- She returned wearing a dab of rouge on each cheekbone.
- She put a dab of butter on the toast.
- Place a dab of petroleum jelly on the bulb.
- She put a dab of perfume behind her ears.
- She gave me a dab of potatoes with my supper.
- Put a dab of glue on each corner.