change做动词时,有三种意义：1.更换（衣）；掉换.例如：
He changed his clothes before going out.他出门前会换衣服.
Where do we change?我们在哪里换车?
2.兑换,互换.（此时,change=exchange,无区别）例如：
I changed places with her.我与她互换位置.
/I exchanged places with her.
3.改变；变化.例如：
The wind has changed from north to east.风向由北转东.