He is indignant at suggestions that they were secret agents. [+ at/about]

有人暗示他们可能是特务,这让他非常气愤。

MPs were indignant that the government had not consulted them.

政府没有事先征求他们的意见,下院议员们感到很愤怒。

Sheena gave her an indignant look.

希娜愤怒地看了她一眼。