feed change gearbox

例句：

1. 1. The baby needs to be fed every two hours.
   宝宝需要每两小时喂一次。
2. 2. The farmer feeds his cows with grass and hay.
   农民用草和干草喂养他的牛。
3. 3. The old man feeds the birds in the park every morning.
   老人每天早晨在公园喂鸟。