1.It was four o'clock, the hour at which his father had always called him to get up and help with the milking. Strange how the habits of his youth clung to him still!

【参考译文】是4点钟，以前在这个时候，父亲总是叫他起床帮他挤奶。好奇怪啊，年轻时的习惯还这么紧紧地攫住他！

【结构解析】“ at which...”做定语修饰“ the hour”，"have always done sth."表示“过去一直...”，“Strange how...”相当于"How strong the habits...still!"

2. He had not known it until one day a few days before Christmas, when he had overheard what his father was saying to his mother.

【参考译文】这一点是圣诞节的前几天才知道的，他无意中听到父亲和母亲的对话。

【结构解析】"not...until"意思是“直到...才...”，例句：It was not until yesterday that I noticed it. 直到昨天我才注意到这件事。