a stagnant pool of water的用法和样例：
- Mosquitoes lay thir eggs in stagnant pools of water.
- A stone dropped into a quiet pool of water.
- In fact, we have some tantalizing evidence that algal blooms occurred in the stagnant pools of water that drew the animals together.
- The pool of water on the playground evaporated in the sun.
- The pot was sitting in a pool of water.