A SPACE 间隔, a space between two objects or two parts of an object, especially because something is missing

缺口，开口，裂缝:

The neighbors' dog got in through a gap in the hedge.

邻居的狗从树篱的缺口钻了进来。

a gap in the traffic

车流中的一个空档

the gap between the two rows of seats

两排座位之间的间隔;

DIFFERENCE 差别, a big difference between two situations, amounts, groups of people etc

差距; 差额; 差别;

the widening gap between the rich and the poor

贫富之间越来越大的差距

His films attempt to bridge the gap between tradition and modernity.

他的影片试图弥合传统和现代之间的差距。

The gap has narrowed to just 12 points now.

现在比分差距缩小到只有 12 分了。

It seems that the trade gap is widening (=the difference between the amount a country imports and exports) .

看来贸易逆差在扩大。

STH MISSING 缺少的东西, something missing that stops something else from being good or complete

空白，缺漏:

There are huge gaps in my knowledge of history.

我的历史知识有很大的欠缺。

Frank's death has left a big gap in my life.

弗兰克的去世给我的生活留下一片很大的空白。

He filled the gap left by Hirst's retirement.

赫斯特退休后他填补了空缺。

IN TIME 在时间上, a period of time when nothing is happening, that exists between two other periods of time when something is happening

时间间隙，时间间隔:

an awkward gap in the conversation

谈话中出现的一次令人尴尬的冷场

The gaps between his visits got longer and longer.

他来探访的时间间隔越来越长了。

IN A MOUNTAIN 在山中, a low place between two higher parts of a mountain

峡谷; 山口

gap in the market, a product or service that does not exist, so that there is an opportunity to develop that product or service and sell it

市场空白