问题标题:
It'sdifficultforustoswima___theriverintwentyminntesThebuildingswereb___lastyearbytheworkers.
问题描述:
It'sdifficultforustoswima___theriverintwentyminntes
Thebuildingswereb___lastyearbytheworkers.
沈海澜回答:
across
built,build的被动式
It'sdifficultforustoswima___theriverintwentyminntes
Thebuildingswereb___lastyearbytheworkers.