The bridge which______ (build) last year looks really beauti

The bridge which______ (build) last year looks really beautiful.为什么不能填had been build

应该用was built,此句last year 是一个时间点,而不是时间段,不能用表示时间段的动词完成时形式.另一方面翻译成汉语也不通,总觉得很别扭,不是吗?
翻译：The bridge which was built last year looks really beautiful.去年修的那座桥很漂亮.The bridge which had been build last year looks really beautiful.去年已经修完的桥很漂亮.
再问： 那last year 就不能用在过去完成时吗？可以的话 麻烦你举个例子 比较好理解 谢谢
再答： 用完成时态的话必须是表示时间段的，可以将last year改成during last year，就表示”去年“这个年头了。