An aperture, or a hole.

隙；孔。

A space in a forest where there are few trees and little undergrowth.

【美】林间空地。

The first steps; beginning.

初步；开始。

The first occasion.

第一次；开幕。

Any opportunity or a chance.

机会；机遇。

An unfilled position in a business organization.

(职位的)空缺。

First in order.

第一次；开头的。