这座桥是通往山村的唯一门户。

The bridge is the only ___gateway to the mountain village.

这个防火墙充当内部网络和外部互联网之间的网关。

The firewall serves as a ___gateway between the internal network and the external internet.

掌握英语可以成为通往国际职场的门户。

Learning English can serve as a ___gateway to international job opportunities.