黄曲霉素AFTB（化学式为C_l7H₁₂O₆）是大量存在于霉变的大米、花生中，人类的特殊基因在黄曲霉素的作用下会发生突变，继而转化为肝癌．

（1）黄曲霉素由______种元素组成，其分子式共有______个原子，其相对分子质量为______；

（2）黄曲霉素分子中氧元素的质量分数为______（精确到0.1%）

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。

     It was a sunny Saturday afternoon in Oklahoma City.My friend,a __1__(pride)father,Bobby Lewis was taking his two little boys to play miniature golf(小型高尔夫球)．__2__(walk)up to the fellow at the ticket counter,he asked,"How much is __3__to get in?"

     "Three dollars for you and three dollars for whoever is older than six," the young man replied,"We will

let them in free __4__they are six or younger.How old are they?"

     Bobby replied,"One is three and the __5__is seven,so I guess I need to give you six dollars."

     The man at the ticket counter said with a surprised look on his face,"Hey,did you just win __6__prize

or something?You could have saved yourself three dollars.I wouldn't have known the __7__(differ)if you

hadn't told me that the older one was seven."Bobby replied,"__8__(sound)true,but the kids would have

known that."

     In challenging times __9__ethics(道德准则)are more important than ever before,you'd better make

sure you set a good example __10__everyone you work and live with.