by the time he took a shower ,his sister had had breakfast .(对第一句部分提问）格式；（）（）his sister （）（）?
问题描述：
by the time he took a shower ,his sister had had breakfast .(对第一句部分提问）
格式；（）（）his sister （）（）?
答
When had his sister had breakfast?
过去完成时：had +动词过去分词
答
When had his sister have breakfast?