And they wanted to use a soluble salt of citric acid, so they could have used sodium, they could have used potassium.

而且他们想用一种柠檬酸的可溶性盐，他们本可以用钠，也可以用钾。

麻省理工公开课 - 化学原理课程节选

The rest of these examples refer to receptors as I've been describing them and ligands that are soluble and can move around the body.

我接下来要讲的有关受体,以及能游走于体内各处可溶性的配体

耶鲁公开课 - 生物医学工程探索课程节选

Here, there are receptors on one cell and the ligand that they experience is not a dissolved molecule, but actually a molecule that's attached to another cell.

这个细胞上有许多受体,与之结合的配体并非是可溶性分子,而是一个附着在其他细胞上的分子

耶鲁公开课 - 生物医学工程探索课程节选