Usar "become stale" en una oración

1. would become stale and stagnant

2. By the end of the trip, the passenger ship’s systems were no longer keeping up with the load and the air in the ship had started to become stale with CO2 reaching uncomfortable levels

3. experience and thrills, that the mind become stale and

4. They are inadequate to sustain you, and they always become stale over time