太阳能被认为是核能的一个可行替代方案。

Solar energy is considered a ___viable alternative to nuclear power.

这家初创公司向投资者展示了一个经济上可行的商业计划。

The startup presented an economically ___viable business plan to investors.

这是一个需要合理答案和可行解决方案的问题。

This is a question that demands reasonable answers and ___viable solutions.