Although ____ thirty years ago,the house looks very beautiful.(build)答案上给的是 built我不明白为什么不能填 to be built或being built以及 to be built being built
问题描述：
Although ____ thirty years ago,the house looks very beautiful.(build)
答案上给的是 built
我不明白为什么不能填 to be built或being built
以及 to be built being built
答
这是关于非谓语动词的用法。to be built用在将来时，表示“将要被建”；
being built则表示“正在被建”。
而且这个句子中“thirty years ago”是过去的某个时间，built是表示“过去被建”，符合语法的要求，所以用built。
答
这是一个省略句，省掉了主语和部分谓语动词（ the house was）！
答
to be built是将来时态,to be done表将来
being built 正在建
答
Although _the house_was built__ thirty years ago,这局话是有省略,为了让句子简洁