infra-,低于，在下方，structure,结构。引申词义基础结构，基础设施。

1. The infrastructure, from hotels to transport, is old and decrepit.

从宾馆到交通，所有的基础设施都已陈旧失修。

2. Japanese proprietors are erecting a complex infrastructure of political influence throughout America.

日本商人正在美国各地建立复杂的、具有政治影响力的基础结构。

3. Vast sums are needed to maintain the infrastructure.

保养基础设施需要巨额款项.

4. The basic technology to support this method is the public key infrastructure ( PKI ).

而基于非对称加密体制的公钥基础设施 ( PublicKey Infrastructure:PKI ) 为这种思路提供了最底层、最基本的支撑技术和手段.

5. Years of civil war have wrecked the country's infrastructure and destroyed its social fabric.

经年内战已破坏了国家的基础设施，摧毁了其社会结构。