The problem is that these stable orbits would only exist once you have crossed the threshold of the event horizon, where time and space flow into one another.

问题是，只有曾穿过黑洞视界的临界才会存在稳定轨道，那里时间与空间会流入其他地方。

youdao

The CBO figures show that this is a big problem with the House plan, whose shortfall will balloon beyond the ten-year horizon.

国会预算办公室的数据显示众议院提出的这项计划有一个很大的问题，就是在十年之后他的赤字会迅速增加。

youdao

The problem is that this is not on the horizon.

问题是，这是不是在地平线上。

youdao

But there is a problem looming on the horizon for fans of the latest tablet computers, not to mention smart phones and flatscreen TVs.

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He said the age profile of current foster carers was a concern for the future as fewer younger foster carers were being recruited, which was "a real problem looming on the horizon".

BBC: Foster care motion concluded

We don't know what we're going to inherent from President Bush, but there is a big problem looming on the horizon that we had better pay attention to, and that is President Bush is intent upon negotiating a long-term agreement with Iraq which would have permanent bases, permanent troop presence.

CNN: Part 2 of CNN Democratic presidential debate