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

Its capabilities for performing navigation of web（）

A．browsers

B．servers

C．hypertexts

D．clients

贴电阻片处的应变为l500με，电阻片的灵敏系数K=2.0，在这个电阻片上应产生的电阻变化率应是（）。

A．0.2% 

B．0.4% 

C.0.1% 

D.0.3%