It provided for the train traffic order and ensured traffic safety. At present, the signal design of train control system needs continuous field tests to be improved.

目前列控系统的信号工程设计需要通过不断的现场试验进行完善，这样做的结果是会消耗大量人力和物力。

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But also taking into account the military aspect of it, we've -- the object eventually, obviously, is to train Afghan national -- an Afghan national security force, army, and police, in order to ultimately transfer control to someone.

WHITEHOUSE: Press Briefing