1. 缝隙；缺口；豁口；裂口
    A gap is a space between two things or a hole in the middle of something solid.

    e.g. He pulled the thick curtains together, leaving just a narrow gap.
           他拉上厚厚的窗帘，仅留下一条狭窄的缝隙。
    e.g. ...the wind tearing through gaps in the window frames.
           从窗框缝隙中呼啸而入的风

2. （时间上的）间断，间隔，间隙
    A gap is a period of time when you are not busy or when you stop doing something that you normally do.

    e.g. There followed a gap of four years, during which William joined the Army.
           随后的4年时间，威廉在陆军服役。

3. 漏洞；空白；缺口
    If there is something missing from a situation that prevents it being complete or satisfactory, you can say that there is a gap .

    e.g. We need more young scientists to fill the gap left by a wave of retirements expected over the next decade...
           我们需要更多年轻的科学家来填补预计未来10年退休高峰带来的人才缺口。
    e.g. Like a good businessman, Stewart identified a gap in the market.
           像精明的商人一样，斯图尔特发现了市场上的一个空白。

4. 分歧；差距；隔阂
    A gap between two groups of people, things, or sets of ideas is a big difference between them.

    e.g. ...the gap between rich and poor...
           贫富差距
    e.g. America's trade gap widened...
           美国的贸易逆差加大了。