To become used up

Perhaps it is time for farmers to put their feet up now that robots are used to inspect crops, dig up weeds, and even have become shepherds, too.

现在，机器人已经被用来检查作物、铲除杂草，甚至还能牧羊，也许农民是时候停下来休息了。

Guards set up a slalom course of barriers to slow truck traffic at the most heavily used crossing sites. Nevertheless, elephants, rhinos, pythons, and deer on the move become roadkill most every year.

在某些车流量较大的十字路口，守卫们都设置了回旋障碍，以减慢车速，即便如此，每一年都会有不少的大象、犀牛、蟒蛇和鹿被车辆轧死在路上。

We have become so used to defending ourselves against the new atmosphere of American life, so used to putting up barriers, that we have not had time to think about what it may mean.

我们已经非常习惯于保护自己不受美国生活新气氛的影响，习惯于围起屏障，却没有时间去考虑这一切意味着什么。