请大家帮我分析这句,when、that、which各在里面起什么作用,when的里面翻译什么意思,谢谢
问题描述：
请大家帮我分析这句,when、that、which各在里面起什么作用,when的里面翻译什么意思,谢谢
when the woman shook her head in bewilderment, harry went on to explain that 'myrolite' was a hard, amber-like substance which could be used to remove freckles.
答
这是一个WHEN的从句（三个从句并列）,没有主句.THAT和WHICH都是引导定语从句