结果表明，经过大修改造的漏斗车可延长有效使用期。

The result shows that the effective service life of the overhauled and reformed hopper car can be prolonged.

但是，美国垦务局不同意大坝只有50年使用期的说法。

But the U.S. Bureau of Reclamation disagrees that 50 years is an advanced age for a dam.

在减少能量要求的同时，还可以延长驱动系统的使用期。

As well as cutting energy requirements this also extends the life time of the drive system.

标签上警告使用者每天用量不要超过八片，而且使用期不要超过两天。

The label warns users not to take more than eight tablets per day and not to use the medication for more than 48 hours.

年久的弹头到了2008年将达到设计的30年使用期，这些旧弹头也就在没有危害国家的核屏蔽的情况下被淘汰。

The older warheads, the most elderly of which will reach the end of their 30-year design lifespan in 2008, could then be retired without compromising the country's nuclear shield.