读“世界人口分布图”，回答下列问题。

（1）世界人口最稠密的四个地区是：                                                                                               等。

（2）图中A、B、C、D四地，人口稀少的原因是：

    A                                                                                                                                                        

    B                                                                                                                                                         

    C                                                                                                                                                         

    D                                                                                                                                                         

（3）亚洲、非洲和拉丁美洲国家人口增长较快，产生的问题是                                                               

                                                                                                  ，解决的措施是                            。