碳元素可形成多种单质和化合物．

（1）天然存在的最硬的、可用来裁玻璃的物质是______（填名称）．

（2）电车与电缆接触的部分称作“电刷”，制作“电刷”的物质是一种碳的单质，这种碳单质是______（填名称）．该物质应该具备的性质是______（填序号）．

①硬度大    ②导热性    ③导电性

（3）目前市场上流行的竹炭是将毛竹高温炭化而成的疏松多孔、表面积大的固体物质．放置在汽车、房间、衣橱内可以除潮汽、异味，说明竹炭具有______性．

（4）古代一些书法家、画家用墨（用炭黑等制成）书写或绘制的字画能够保存很长时间不变色，这是由于______．

（5）一氧化碳常用于冶金工业，写出利用一氧化碳还原氧化铜的化学反应方程式______．

The（）is a general description of the architecture of a workflow management system used by the WFMC, in which the main components and the associated interfaces are summarized. The workflow enactment service is the heart of a workflow system which consists of several（）. In a workflow system, a process is specified using the process definition tool. Usually, processes are defined in terms of a（）, which consists of（）indicated using a circle, and（）shown as a rectangle. These two components can be linked by means of a directed arc.

processes are defined in terms of a（）

A．PERT diagram

B．DFD

C．Petri Net

D．ER diagram