文献检索是以科学的方法，利用检索工具和（），从有序的文献集合中检出所需的信息的一种方法。

A.文献收集

B.文献鉴别

C.检索系统

D.文献加工

Rapid application development (RAD) systems purport to lighten the developer’s (46) by making it easy to program an application with simple intuitive steps.
RAD tools (47) the developer everything needed to construct a fully functional application quickly and easily. They make short work of modifying the developed product to (48) changes after the program is finished. Applications developed with RAD tools are constructed as they are envisioned. As an application’s real usefulness (49) , the developer armed with RAD tools should be able to (50) on new features with little fuss.

A．accommodate

B．account

C．decrease

D．eliminate