a drop quiz的用法和样例：
- A drop of blood slid down his leg.
- He made up his mind never to touch a drop of drink.
- The candidate got a drop on his opponent by announcing first.
- His father chased down a glass of wine with a drop of water.
- A drop of milk diffused in the water, and it became cloudy.
- A drop of ink spreads on the paper.
a drop quiz的相关资料：