In Europe it took a little longer, mainly because there were more small producers for whom the costs of sound were prohibitive, and in other parts of the world problems with rights or access to equipment delayed the shift to sound production for a few more years. (though cinemas in major cities may have been wired in order to play foreign sound films) (TPO12, 63)

prohibitive /prə'hɪbətɪv/ adj. (指价格等)高得买不起的;禁止性的

我是分界线，大家先自己一遍速读哦。

(In Europe) it took a little longer,(mainly because there were more small producers) (for whom the costs of sound were prohibitive),and ( in other parts of the world) problems (with rights or access to equipment) delayed the shift to sound production (for a few more years) ( though cinemas in major cities may have been wired in order to play foreign sound films). (TPO12, 63)

分析：

本句的主干就是一个并列结构：it took a little longer and problems delayed the shift to sound production

修饰一：(In Europe)，介词短语

修饰二：(mainly because there were more small producers)，从句

中文：主要是因为有更多小的制造商

修饰三：(for whom the costs of sound were prohibitive)，从句，修饰produces

中文：对于他们来说转换声音的成本巨大

修饰四：(with rights or access to equipment)，介词短语，修饰problems

中文：专利权以及设备的问题

修饰五：(for a few more years)，介词短语

修饰刘：(though cinemas in major cities may have been wired in order to play foreign sound films)，括号，解释说明

中文：虽然在很多大城市的影院为了播放国外有声电影已经用线装好了设备

参考翻译：

欧洲花得时间要长一些，主要是因为有更多小的制造商，对于他们来说转换声音的成本巨大。在世界其它部分，专利权以及设备的问题延迟了向声音产业转变很多年。(虽然在很多大城市的影院为了播放国外有声电影已经用线装好了设备)

这个句子的主要修饰成分就是从句、介词短语，大家务必想清楚，每一个修饰成分修饰的是什么，才能看清楚这个句子的结构。