There is only a narrow entrance to the black hole.

黑洞只有一个很窄的入口。

You need a lagoon with a very narrow entrance and that you have there.

这里应该有入口很窄的泻湖，但那里才有。

They then blocked the narrow entrance  and the exit points to the plaza.

然后他们封锁了通往广场的狭窄入口和出口。

It's massive in size, the waters within it are deep and can easily accommodate warships and submarines and it's extremely well protected from the furies of the outside ocean through a single narrow entrance.

它面积巨大，水深，可以轻松容纳军舰和潜艇，而且通过一个狭窄的入口，可以很好地抵御外海的狂风骤雨。

For the 2012 London Olympics, Brett designed a system to move crowds of up to 15,000 people to and from a venue down a narrow sidewalk, across a road, and through a narrow station entrance.

在2012年伦敦奥运会上，布雷特设计了一套系统，可以让多达15000人的人群沿着狭窄的人行道往返会场，穿过一条马路，再通过一个狭窄的车站入口。