该地区的教育标准已经开始下降。

Educational standards in the region have begun to ___fall.

历经多年荒废，这座历史悠久的宅邸已破败不堪。

After years of neglect, the historic mansion has ___fallen into ruin.

自从新大楼启用后，旧的市政厅就废弃不用了。

The old town hall has ___fallen into disuse since the new building opened.