下面的短文有十处错误。错误涉及一个单词的增加，删除或修改。

增加：在缺词处加一个漏字符号，并在其下面写出该加的词。

删除：把多余的词用斜线划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

Do you often smile? If not, star smiling now. People who like smiling and often smile not only leave a friendly impression to others, but also changing their own mood. As a result, facing with great pressure from my work, I held the view that we should smile happily. A few days ago, while chatted with one of my friends on the internet, I expressed my dissatisfaction with my job. After learning from this, he sent me his picture with big smile. The pictures changed my bad mood immediately. From the above example, we can know whether we smile to life, life can give me a big reward.  

当中央油箱供油时机翼油箱燃油泵是否工作（）

A.工作，机翼油箱燃油泵一直工作；

B.不工作，只有当中央油箱空了时才工作；

C.不工作，因为中央油箱燃油泵有优先权。