Once this plant is grown, it has a useful lifespan of several decades.

As they are a show and companion breed, their "useful" lifespan is not limited.

The useful lifespan of the bridges, once complete, is thought to be 500-600 years.

Gas masks have a limited useful lifespan that is related to the absorbent capacity of the filter.

The tree can measure up to 25 m in height, 0.7 m in diameter and have a useful lifespan of 60 years.

While the cars have reached the end of their useful lifespan, the authority is overhauling them to save money.

These tenants have all said that the Dome is nearing the end of its useful lifespan.

I'm *unhappy* with anything that prolong's IE6's useful lifespan, but this could be useful to some people.

Now the spacecraft uses less fuel to maintain a stable orbit, increasing its useful lifespan to more than 40 years.

True, nearly every Funnel has limited useful lifespan, as countless amateurs keep finding and rendering them useless.