写出下列反应的化学方程式

（1）乙烯的水化______

（2）丙烯的加聚反应______

（3）苯的溴代______

（4）甲苯的硝化______

（5）苯乙烯与足量氢气反应______

（6）乙烯的实验室制取原理______．

Many of the activities performed during the preliminary investigation are still being conducted in(1),but in much greater depth than before. During this phase, the analyst must become fully aware of the (2) and must develop enough knowledge about the (3)and the existing systems to enable an effective solution to be proposed and implemented. Besides the(4)for process and data of current system, the deliverable from this phase also includes the(5)for the proposed system.

空白（4）处填（）

A.logicalmodels

B.physicalmodels

C.designmodels

D.implementationmodels