Why so many youths are _____ on playing computer games often puzzles us a lot.

Judging from his _______ look, I know it is a very _____ situation to her.

--- Have you seen the robber______?--- Why ask me?  You are the only one who stands _____ to him.

Please keep ______; I’m taking a photo of you all. Say “Cheese”.

The government should develop          system to predict when wildfires occur andgive warnings in time.