It took only four years to complete the construction of the Beijing-Zhangjiakou Railway ahead of schedule, and the cost of the project was only one fifth of that estimated by foreigners.

It took only four years to complete the construction of the Beijing-Zhangjiakou Railway ahead of schedule, and the cost of the project was only one fifth of that estimated by foreigners.
A.正确
B.错误
正确答案：正确