The time is not far away _______ the news will be made known ________ will represent our company to attend the coming medical conference to be held in Beijing.

A．until; who

B．when; who

C．before; which

D．when; whenever

汽轮机在运行中，如果发现真空降低到某一数值后就不再继续下降了，可认为（）有不严密的地方漏入空气。

A.凝汽器

B.回热系统

C.管道阀门

D.再热系统