When we fill bottles with water from streams and lakes, we deal with the risk of parasites by treating the water with a filter or chemicals, or by boiling it.

• 当我们到小溪把溪子里的水装满时，我们用过滤器或是药物来处理寄生虫，或是把水煮开杀死虫子。在户外，我们与熊共处，既要保护我们自己，又要不伤害熊。