WebSQL is a SQL-like (26) language for extracting information from the web. Its capabilities for performing navigation of web (27) make it a useful tool for automating several web-related tasks that require the systematic processing of either ail the links in a (28) , all the pages that can be reached from a given URL through (29) that match a’ pattern, or a combination of both. WebSQL also provides transparent access to index servers that can be queried via the Common (30) Interface.

（30）是（）

A.Router

B.Device

C.Computer

D.Gateway

与北方地区相比，南方地区农业的优势在于[ ]

A．地势平坦，土壤肥沃

B．交通便利，人口众多

C．热量充足，降水丰富

D．历史悠久，技术先进