You may have seen some of these details and wondered what they were for - the tiny holes in a plane window for instance.
日常生活中你可能会注意到一些小细节并对它们的用途困惑不已——例如飞机窗户上的小洞。
Others you may not have noticed at all - like the tiny hole on the base of a padlock.
还有些细节你压根就没发现——例如挂锁底下的小洞。
But all of them have important functions, some potentially life-saving.
但是这些小细节都有至关重要的作用,有些可能还可以救命。
The small hole at the end of biro pen, for example, is there in case a child accidentally swallows it, to provide an air hole so they can still breathe with it lodged in the throat; while the hole in a plane window is to prevent it from imploding should one of the three panes break.
Others are game-changing in terms of their usefulness. That small triangle on your petrol gauge, for example, indicates what side of the car to access your pump from, so you'll never have to get out of a hire car to check again.