读漫画“愁”，回答下列问题：

（1）地球母亲为何发愁？                                                                                                    

（2）这幅漫画揭示了世界各国共同关心的问题是________   、            ___。

（3）我国是否存在这些问题？________。原因是____                                                              _______   

                                                                                                                                                            。

（4）解决这些问题的主要途径有_____________________                                                              ____   

                                                                         。