when是什么意思

　　when例句分享

　　When will the single currency be operable?

　　什么时候实行单一货币？

　　You did well to sell when the price was high.

　　你在价钱高的时候出售，真明智。

　　When studying abroad I was often sick for my home.

　　我在留学期间常常想家。