单选题 ①John Roebling planned to build the Brooklyn Bridge before 1867. But he never really gotstarted. In 1869 , he died of an accident. The job fell to his son Washington , a master of construction.In 1872 , Washington was injured in building the bridge. He could not walk any longer. He could onlysee the building of the bridge from his window. But his mind was still fresh. How could he get hisideas down to the workers?

②That' s where Emily came in. Emily and W ashington married in 1865. At that time John wasplanning the bridge. He sent his son around the world to study bridges. Emily went along with herhusband and learnt much about bridge building. When John died and Washington became the boss,she taught herself more about bridge building. She wanted to help her husband with his new job.

③Emily regularly came to the building site. She gave Washington' s instructions to the workers.And then she took questions back to him. However , as time went on , her role started to change. Soon,workers saw her as the new boss. As she had more and more knowledge , she became the chiefengineer. She met with officials ,discussed with other engineers , and instructed the workers.

④Emily also helped to solve problems outside the building site. Some people once questioned her husband's ability to head the bridge building. And the American Society of Civil Engineerswould think about replacing him. Emily. went to meet the group. She gave a speech in defense of her husband. The group finally decided to keep him on the job.

⑤It took up 14 years to build the bridge. For 11 of those years , Emily was the one in charge.The bridge finally opened on May 24 ,1883. She was one of the first people to cross the bridge. Emilynever planned on becoming an engineer,but she turned out to be a great one.

As time went on,______.