钱文忠在《让汉字高兴一会儿》中写道：“囧，我很囧。这个字非常有意思，真的奇思妙想，它的本义是光明的……这个字早就退出历史舞台，没人用了。”古字新用，像当下“囧”字这样的奇思妙想（    ）

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    My name is Bill. I am a student in No. 10 Middle School. I am very busy this 1. On June 3rd, we 2 a school trip. I need to buy some food 3 the trip. On June 6th, we have a P.E. test. I am a fat boy, so it is really 4 for me. June 15th is my twelfth 5. I ask my friends to 6 to my party. I need to buy some things for my party in the 7. June 26th is my friend Alan's birthday. I know 8 like(s) ping-pong. I want to buy a ping-pong bat for him. On the last day of June, June 9, my school has a book sale in the school library. I can buy some books at good 10. I hope (希望) I can have a good time this month.

某中学为了表彰在书法比赛中成绩突出的学生，购买了钢笔30支，毛笔45支，共用了1755元，其中每支毛笔比钢笔贵4元．

（1）求钢笔和毛笔的单价各为多少元？

（2）①学校仍需要购买上面的两种笔共105支（每种笔的单价不变）．陈老师做完预算后，向财务处王老师说：“我这次买这两种笔需支领2447元．”王老师算了一下，说：“如果你用这些钱只买这两种笔，那么帐肯定算错了．”请你用学过的方程知识解释王老师为什么说他用这些钱只买这两种笔的帐算错了．

②陈老师突然想起，所做的预算中还包括校长让他买的一支签字笔．如果签字笔的单价为小于10元的整数，请通过计算，直接写出签字笔的单价可能为多少元．

“x＜－1”是“x²－1＞0”的  (　 　)