建成以来，该桥经受了多次洪水和地震，但其主体结构仍然完好无损，至今仍在使用。
Since the completion, the bridge has withstood floods and earthquakes, but remains intact in its main  structure and still available in use. 
Since  the bridge was completed, the bridge has withstood floods and earthquakes, but its main structure  remains intact,  used until now.
The first English sentence is a better translation.
A、正确
B、错误