阅读下面短文，按要求完成各项任务．

    Everywhere in the world there are different ways of behaving．When we meet someone，everything we say and do expresses our cultural background．So if you want to get on with someone from another culture，it helps to understand something about these differences．

    Even how we stand depends on our culture．English people talk to each other at an average （平均的） distance of 130 cm，while Italians chat at an average distance of 80 cm．So Italians can think that English people are unfriendly because they stand too far away!And English people can think that Italians are too close．

    Touching is also cultural．The French touch much more than Americans．A French couple may touch 100times in half an hour while an American couple may only touch twice!And French teenagers touch each other much more than American teens．

2004年12月7日21时35分，两艘外籍万吨级集装箱船在珠江口担杆岛东北约8海里处发生碰撞，溢出燃油约450吨，造成我国最大的船舶碰撞溢油事故。交通部牵头全力组织清污，采用围油栏截污、向海上洒消油剂和吸油毡等来清除油污。据此回答以下小题。

Mr Li is a doctor.

He goes to work at eight o'clock ____ ____.

从人类文明的起源到奴隶社会的形成，我国的原始社会经历了一个漫长的时期。据此回答下列问题：
（1）我国的人类文明起源于哪一原始人类？ 生活在哪个流域？
（2）写出三个你所知道的我国远古人类代表。
（3）我国原始农耕时代的两项世界性的贡献是什么？
（4）我国奴隶社会开始于哪一年？ 开始的标志是什么？