With the development of science and human civilization, many formerly unimaginable

　　things come into reality. Some of them have positive effects on our life, but some are

　　distasteful. The phenomenon of ___________ (主题现象) is an example of the former / latter

　　one.

　　There are many factors that may account for it, and the following are the most

　　conspicuous aspects. To start with, __________________ ( 原因1). Furthermore,

　　______________________ (原因2). Eventually, ________________________________ (原

　　因3).

　　Good as ____________ (主题现象) is, it has, unfortunately, its disadvantages. The

　　apparent example is that ______________ ( 缺点例子1). In addition,