语法总结
By + 过去时间 + 过去完成时被动
By 1884, ... had been erected 强调到某一过去时点之前动作已完成。
相似句：
- By 1900, the bridge had been completed.
- By then, the work had been finished.
Ever since then + 现在完成时
has been a symbol... 表示从那时起一直持续到现在。
相似句：
- Ever since then, he has lived there.
- Ever since then, the building has been famous.
which 引导定语从句
which was designed by... / which was 151 feet tall 都让说明更具体。
相似句：
- The house which was built in 1890 still stands.
- The girl who won the prize smiled shyly.