The process of integration has the nature of arduousness and protractiveness.一体化进程有其艰巨性和长期性.But we must see complexity and arduousness of this process.但必须看到这一过程的复杂性和艰巨性....

艰难，艰苦，奋斗...

arduousness的音标：arduousness的英式发音音标为：['ɑ:djʊəsnɪs]arduousness的美式发音音标为：['ɑdjʊrsnɪs]...