用when造句并回答、翻译。

fifteen dollars on me when the book I wanted cost twenty.我身上只带了十五美元,可是我想买的那本书定价二十美元。Since when has she taught here?她从什么时候开始在这儿教书的?When did you came here?你什么时候来这里的？When I was sleeping, you came here.我睡觉的时候你来这里了。