thousand与数词连用时，不加s
例句：There are two thousand doctors and nurses working hard in that hospital.
句意：在那家医院里有两千名正在努力工作的医生和护士。
thousand与基数词搭配表示具体数目，不用复数thousands of意为“成千上万的”，表示不确定的数字
例句：
The earthquake let thousands of people homeless.
句意：这场地震让成千上万的人无家可归。
