1. 地平线
    The horizon is the line in the far distance where the sky seems to meet the land or the sea.

    e.g. A grey smudge appeared on the horizon. That must be Calais, thought Fay...
           一个模糊的灰影出现在地平线上。那里一定是加来，法伊心想。
    e.g. The sun had already sunk below the horizon.
           太阳已经落到了地平线下面。

2. 范围;眼界;见识
    Your horizons are the limits of what you want to do or of what you are interested or involved in.

    e.g. As your horizons expand, these new ideas can give a whole new meaning to life...
           随着眼界不断开阔，这些新观念会为生活赋予全新的意义。
    e.g. By embracing other cultures and genres, we actually broaden our horizons, rather than narrow any existing ones.
           通过接纳其他文化和体裁，我们实际上拓宽了领域，而不是让现有的范围变得狭窄。

3. 已露端倪的;即将发生的
    If something is on the horizon, it is almost certainly going to happen or be done quite soon.

    e.g. With breast cancer, as with many common diseases, there is no obvious breakthrough on the horizon...
           对乳腺癌等很多常见疾病来说，目前还看不到有明显的突破。
    e.g. Suddenly, with war on the horizon, the army seemed in danger of disintegration...
           随着战争即将爆发，军队似乎突然面临分崩离析的危险。