作文：

       人生道路上，总有一些人、一些事，甚或一句话、一本书、一则故事、一个微笑、一种执着的追求、一次慰藉人心的宽容……在不经意间触动你的内心，启迪你的灵魂，点亮你的心灵。

       要求：①以“点亮心灵的灯”为题写一篇600字左右的记叙文。  ②文中不要出现真实的人名、地名、校名等透露个人身份的信息。

小鼠杂交瘤细胞表达的单克隆抗体用于人体试验时易引起过敏反应，为了克服这个缺陷，可选择性扩增抗体的可变区基因（目的基因）后再重组表达。下列相关叙述正确的是 （　　）

    American people like to say "Thank you " or say something kind when others help them．People of many countries do so，too．It is a very good habit．
    You should say"Thank you'when someone passes you the salt on the table，when someone walking ahead of you keeps the door open for you and when someone says you always do your work well or you have a nice thing or your city is very beautiful．“Thank you”is used not only between friends，but also between parents and children，brothers and sisters．
    “Excuse me”is another short sentence they use．When you hear someone says“Excuse me”behind you，you know that someone wants to walk past you without touching you．It’s not polite to break(打断)others when they are talking．If you want to speak to one of them。say‘Excuse me’first，and then begin talking．You should also do so when you begin to cough or make any noise before others．
Let‘s learn to say‘Thank you’and‘Excuse me’．