完形填空常用介词的语法知识梳理:答:1、in 表示一段的时间 如:in the morning, in the afternoon, in the evening, in October, in 1998, in summer, in the past, in the future 等。on 总是跟日子有关,on Monday, on Christmas morning, on the following, on May Day, on a warm morning 等。at 如: 常用词组有: ...