第一个有交换的意思,第二个改变,更换
exchange
交换;调换;兑换[(+for/with)]
I'd like to exchange some pounds for dollars.
我想把一些英镑兑换成美金.
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change
换;交换,互换[(+for)]
We changed seats in the interval.
中间休息时,我们交换了一下座位.
On second thoughts he changed his mind.
进一步考虑后,他改变了主意.