一、lose at (v.+prep.) 在…(比赛)中失败 fail to win at (game)。
基本句型： lose at sth：
例：I always lose at cards， with my bad luck.
我不走运，打牌总输。
二、lose by (v.+prep.)因…蒙受损失;因…失去。
基本句型：
1、lose by sth.
例：Put your money into our savings plan， and you can't lose by it.
按我们的储蓄计划把钱存起来，你就不会蒙受什么损失。
2、lose sth by sth.
例：The government may lose seats by the reorganization of voting areas.
政府可能会因为调整选区而失去席位。
三、lose in (v.+prep.)(指某种声音)被(其他声音)淹没，吞没。
基本句型：
1、lose sth/oneself in sth.
例：We lost ourselves in the dark.
我们在黑暗中迷路。
2、lose oneself in sth.
例：I can always lose myself in a good book.
一本好书会使我爱不释手。