if
conj. /ɪf/ A1
如果；若是；是否
Used to say that one thing can happen only when another thing happens.
仙境例句
If Alice ate too much mushroom, she might never fit through a door again.
如果爱丽丝吃太多蘑菇，她也许再也钻不过任何一扇门了。
原著这一句
“I don’t believe it,” said the Pigeon; “but if they do, why then they’re a kind of serpent, that’s all I can say.”
“我才不信，”鸽子说，“就算她们吃，那她们也是一种蛇，反正就这么回事。”
卡罗尔原著 · 第 5 章