Unfortunately, my time is limited.

可惜的是，我的时间有限。

Unfortunately for the Prince, his title brought obligations as well as privileges. [+ for]

可惜对于王子来说，封号赋予他特权的同时也给他带来了义务。

The enclosed photograph is unfortunately not good enough to reproduce.

遗憾的是，附寄的照片不够清晰，无法复制。