我们都知道on是一个介词，主要意思是"在…上面"、"关于…"、还有用在具体的日期前等等。今天在读《杀死一只知更鸟》的时候，书中有这样一段描写：
Walter looked as if he had been raised on fish food: his eyes, as blue as Dill Harris's, were red-rimmed and watery. There was no color in his face except at the tip of his nose, which was moistly pink.
沃尔特看上去像是吃鱼长大的：他的眼睛像迪儿的一样蓝，眼眶红红的，还泪汪汪的。他脸上没有血色，只有鼻尖那儿是潮乎乎的粉红色。
这是一段外貌描写，我们也可以模仿用到我们的写作中去哦。重点要说的是on的用法，常见的用法就不介绍了，下面说说我们不太常见的用法：
1. 服…药
Are you still on antibiotics?
你还在服用抗生素吗？
2. 挣…钱，工资为…
He's on quite a good salary now.
他现在的工作相当高了。
She must be on at least ￥500000 a year.
她一年至少能挣五十万。
3. 乘坐（公共汽车，火车，飞机等）
Did you manage to sleep on the plane?
你在飞机上睡着了吗？
I'll probably come on my bike.
我很可能骑自行车来。
4. 吃…，喝…
They live mainly on beans and rice.
他们主要食用豆类和米饭。
Is your baby on solid food yet?
你的宝宝开始吃固体食物了吗？