与介词to搭配，表示作用于，例如：
1、A bird's wings are comparable in function to a fish's fins.鸟的翅膀与鱼的鳍功能相似。
2、It was her first time to visit the Chinese city， and she said that it was also her first time to use the app's online payment function to pay for the ride.这是她第一次访问这座中国城市，她说，这也是她第一次使用该应用的在线支付功能支付乘车费用。
3、Periscope， an app for smartphones， uses a video function to allow users to stream events scope是一款智能手机软件，用户可以使用视频功能记录生活中发生的点滴。
