I suppose there are many words for it, but I'm annoyed (perhaps at myself) for not already knowing what Dave said I should already know: viz, that xiān jiāo qián means pay in advance, in lesson 3.4. I've searched earlier lessons and, sorry, don't find this phrase. "Fu" was introduced earlier as a word for "pay" in connection with a deposit for a hotel. Later, in 4.3, "jie zhang" is introduced in the bit on a restaurant for "pay the bill", though I'm not sure which is "pay" and which is "bill", or whether nothing here is literal. Can someone enlighten me about the most simple, common way to say "pay"? It's a pretty basic word in modern life.
and p.s. Both Dave and Lin Ping are great! No changes necessary on that score.