some buildings in the past ()down and new ones are being built there

问题描述:

some buildings in the past ()down and new ones are being built there

用现在完成时,表示过去的动作对现在造成了影响.
意思是:过去的楼房已经坏了,那儿正在建新楼房.
Some buildings in the past 【have broken 】down and new ones are being built there.