That he finished writing the composition in such a short time surprised us all.
问题描述：
That he finished writing the composition in such a short time surprised us all.
如题,请分析句子结构,
句子前面的that有什么用额
答
That he finished writing the composition in such a short time这个完整的句子前面加一个that构成了主语从句.
surprised是位于. us是宾语,all是宾语的同位语.
意思：他在这么短的时间里完成了作文,让我们所有人都感到吃惊.