雄关的英文：
impregnable pass

impregnable是什么意思：
adj. 无法攻取的；坚不可摧的，毫不动摇的

To saturate; impregnate.
使饱合;使充满.

She impregnated with viscid isolation impregnation substance
她用粘性绝缘物质浸渍。

treated, coated, or impregnated with rubber.
用橡胶处理，涂上或注入橡胶。

The air of this room is impregnated with damp.
这房间充满着湿气。

To saturate, impregnate, or coat with paraffin.
用石蜡使充满、使饱和或涂抹

pass是什么意思：
v. 通过；传递；及格；经过
n. 穿过，经过；通行证，护照，入场证

This coin will not pass.
这钱币不通用。

pass a messenger
传递引绳

The evening passed as evenings mostly pass at Italian theatres
那一声过得很平淡，象意大利戏院里的大多数夜晚一样

Jan has passed the ball to the teammate, a wonderful pass.
简把球传给了队友，传得可真漂亮。

You could pass for a teenager. The fake painting passed for an original.
你可冒充十几岁的人。这幅伪造的画被当作真品