There are three workers in this factory. My brother is in it too.A. thousandB. thousands

问题补充：

There are three workers in this factory. My brother is in it ,too.

A. thousand

B. thousands of

C. thousand of

D. thousands

答案：

(答案→)A. thousand

B. thousands of

C. thousand of

D. thousands

解析：句意：在这个工厂有三千个工人。三千具体数字，不加s，thousands of，数千，模糊数字，故选A。