Extant questions的用法和样例：
例句
- The application of probiotic bacteria is one of extremely effective ways to solve the extant questions in aquiculture.
益生菌的应用是对水产养殖业现存问题十分有效的解决途径之一。 - Using the Case based reasoning technology during the course of design, people can use experiences to solve current questions.
在设计时能运用基于实例的推理方法，从以往的设计实例中得出与现在问题最相似的实例，用以往的设计经验来解决现存问题。
