Now, there actually is a wonderful salt substitute, at least in terms of flavor.

其实有一种很好的盐替代品，至少在味道方面是这样。

In fact, chemists have been trying to cook up a good salt substitute for decades, and it has proven downright impossible.

事实上，几十年来化学家一直在努力研制好的盐替代品，但事实证明这是完全不可能的。

And the channel's selectivity for sodium is one reason why the best salt substitute out there, potassium chloride, still isn't very good.

通道对钠的选择性是导致最好的盐替代品，也就是氯化钾，仍然不是很令人满意的原因之一。