1.   An air of uncertainty pervades the production.

2.   At the anniversary office the other day, a sleepy air pervaded, as it does in many government offices in the clammy heat just before the summer monsoons.

3.   There is an eerie silence, and an air of gloominess pervades the room.

4.   An air of festivity pervaded at the gaily-decorated KLGCC car park, venue of the flag-off that early morning.