题目

The relationship between students and teachers is very important.Why is getting along with teachers important? Every day, we spend more hours with our teachers at school than with our parents at home.We learn many things from them and they teach us to be good people.In China, many students think that teachers care mainly about our studies and school lives.We believe that they know everything, especially about the subjects they teach.They also have the right to decide who should be the new class leaders, give a speech or take part in some important activities.Many students want to be the teache大道之行也，天下为公。选贤与能，讲信修睦。故人不独亲其亲，不独子其子，使老有所终，壮有所用，幼有所长……是故谋闭而不兴，盗窃乱贼而不作，故外户而不闭，是谓大同。今大道既隐，天下为家。各亲其亲，各子其子，货力为己。大人世及以为礼，城郭沟池以为固……故谋用是作，而兵由此起。禹、汤、文、武、成王、周公，由此其选也。……是谓小康。 ——《礼记》①材料一讲的是哪一个时期？材料二讲的是哪一个时期？                                                               ②这两个时期有什么不同？