only when

• The non-bleed controller uses air only when exhausting the line to the controlled device .
  无放流式调节器只有在通至调节机构的管道排气时才消耗空气。
• The non-bleed controller uses air only when exhausting the line to the controlled device .
  无放流式调节器只是在通至调节机构的管道排气时，才消耗空气。
• I can carry states like that only when i come out of the cities with a big margin .
  我之所以能在这些州里获胜，不过是因为我在城市里也获得了巨大的多数。
• We normally alter price only when it is safe to do so according to industry convention .
  我们一般只在根据工业协定改变价格确实安全的时候，才会去改变价格。
• Only when the last child had disappeared did sister agatha break her rigid pose .
  一直等到孩子们全部走完了，阿加莎修女才放弃了她那僵硬的一本正经的假做作。
• In many nations, there is a "two-class system" in which privilege exists only when it is accompanied by wealth .
  许多国家有“两个阶级制度”，特权只随财富而来。
• This integral can be evaluated, of course, only when the force is known as a function of the time .
  显然，只有知道了力与时间的函数关系后，这个积分才能进行计算。
• Only when a great deal more information has been obtained, will it be possible to plan a manned trip to mars .
  只有在获得大量资料后，才有可能筹划载人的火星之行。
• In a structure with no openings, the loading will cease only when the overpressure drops to zero .
  对没有开口的建筑物来说，只有当超压力降到零时，这种载荷才会终止。
• Lines of force can begin or end inside a region of space only when there is charge in that region .
  只有当这一空间区域内有电荷存在时，电力线才能发自或终止于这一空间区域。