解释下列词语。

①阴霾：                                                                                

②迫不及待：                                                                        

③梦寐以求：                                                                        

④孜孜不倦：                                                                        

试把传统经济体制的形成过程及逻辑，与1970年代末以来的改革过程、顺序以及逻辑相比较。