下面短文中有10处语言错误。请在有错误的地方增加，删除或修改某个单词。

增加：在缺词处加一个漏字符号（/\）, 并在其下面写上该加的词。

删除：把多余的词用斜线（﹨）划掉。

修改：在错的词下划一横线，并在该词下面写上修改后的词。

Some students think a difficult exam is just like a challenge and the more difficult it is, the more better it will be. They say a difficult exam can help them to find out what they are weak in their studies and improve their learning methods. Though, others were against a difficult exam. In their opinions, if it is very difficult, they may become discourage and feel terrible about their studies. I prefer an exam neither too difficult or too easy. A very easy exam is not good of teachers to learn how we are getting on with our studies, and too difficult an exam will make us lose our heart.

在燃烧室内工作需加强照明时，可由电工安设（）临时性的固定电灯，电灯及电线须（），并（），放在（）的高处。安装后必须由检修工作负责人检查。禁止带电移动（）的临时电灯。