Either "understanding" or "an understanding" are acceptable in that sentence. They're not completely interchangeable, though: if you add the ... ... <看更多>

Jancis Robinson - Food And Wine Pairing - An Understanding of Wine - BBC Maestro. 42K views 1 year ago. BBC ... ... <看更多>

Definitions of culture usually incorporate an expression of values and beliefs of groups, the learning that occurs in groups, and the expressions of those ... ... <看更多>