数头羊用英语怎么说

数头羊在英语中被称为"counting sheep"。这个短语的来源源于人们在睡眠困难的情况下常常会尝试用数羊的方法来安抚自己，以此来帮助自己入睡。
下面是一些使用"counting sheep"的例句，并提供对应的中文翻译：
I can't fall asleep. I've been lying in bed for hours, trying to count sheep.
(我睡不着。我躺在床上几个小时了，一直在数羊。)
I've tried everything to get to sleep, but nothing works. I've even tried counting sheep.
(我已经尝试了各种方法才能入睡，但都没有用。我甚至试着数羊。)
I heard that counting sheep is a good way to relax and fall asleep.
(我听说数羊是放松并入睡的好方法。)