这份报告提出了关于环境可持续性的问题。
The report raises the ___question of environmental sustainability.
几个关键问题从我们漫长的会议中浮现出来。
Several key ___questions arose from our lengthy meeting.
城市规划者面临的一个关键问题是如何创建包容的公共空间。
A key ___question for urban planners is how to create inclusive public spaces.