单选题 从下面提供的答案中选出应填入下列英文语句中______内的正确答案。
   Application development increasingly means Windows development, and the popularity of visual development tools has (1) in tandem with Windows itself These tools create beautiful windowing (2) , and their fast development cycles and easy learning curves make them a good (3) for many types of PC development projects. Today's developers are leveraging these tools and the abundance of heap, powerful PCs to shift the balance of power to the desktop.
   As the world moves inexorably toward Windows and other (4) user interfaces, developers can choose from an abundance of (5) oriented tools. Popular examples include Microsoft Corp.'s Visual Basic, Powersoft Corp.'s PowerBuilder, Gupta Technology Corp.'s SQL Windows，and so on.