分析《陈涉世家》第二段，回答问题。

1、（1）导火线是                               。

     （2）陈胜认为起义将取得人民支持的理由是：

        ①                                                                                                                                                

        ②                                                                                                                                                。

     （3）为起义作的舆论准备是：①                                                    ②                                             ，主要作用是：                                                                                                                                       

     （4）提出的起义口号是：                                                                                                                 

2、农民起义的直接原因是：

（1）苛重的兵役，                                                            一句可见摇役之重；

（2）残酷的刑法 ，                                                                说明秦朝法律的苛酷，从而表明起义是被逼的。根本原因是：                                                                                                                              

3、陈胜、吴广谋划起义的主要策略是什么？

（1）                                                                                                                                                    ；

（2）                                                                                                                                                    。