First , americans have become intolerant of large , polluting industrial plants on their doorsteps .

首先，美国人已经不能容忍在其家门口建立大型污染工厂。

Now , many consumers prefer having books delivered to their doorsteps or downloading them to electronic devices by touching a screen .

如今，很多消费者更喜欢图书送货上门服务或通过触摸一个屏幕将图书下载到电子产品中。

Virtually all japanese newspapers are delivered by agents who work on commission , frequently turning up on doorsteps to collect money .

事实上，所有的日本报纸都是由提取佣金的代理商递送的，这些代理商会经常去家家户户收钱。

From reporters on doorsteps to editors reporting to proprietors with political backing , there were pernicious incentives .

不管是大门口的记者，还是直接向拥有政治背景的财主汇报的编辑，均存在有害的激励机制。

To stop them disfiguring the nation 's doorsteps would involve understanding why they get dropped in the first place .

要想让它们不再弄脏英国家庭的门口，首先需要理解它们为何会被丢弃。