阅读下列短文，从每题所给的四个选项(A、B、C和D)中选出最佳选项。
Until I was twelve years old，I thought everyone in the world knew about the grinnies，if I thought about the term at all－which is unlikely. After all，everyone in my family used the word quite naturally，and we understood each other. So far as I knew，it was a word like any other word－like bath，or chocolate，or homework. But it was my homework that led to my discovery that grinnies was a word not known outside my family.
My last report card had said that I was a “C” student in English，but both my parents and teachers decided that no child of theirs would be just an average student of anything. So nightly I spelled words aloud and answered questions about the fine points of grammar. I wrote and rewrote and rewrote every composition until I convinced my mother that I could make no more improvements. And the hard work paid off. One day the teacher returned compositions，and there it was－a big fat，bright red “A” on the top of my paper. Naturally，I was delighted，but I didn't know I was attracting attention until the teacher spoke sharply，“Helen，what are you doing？”
Called suddenly out of my happy thoughts，I said “Oh，I've got the grinnies！” The teacher and my classmates burst into laughter，and then I understood that grinnies was used inside my family. Other people were not so lucky.
And it is really lucky to have the grinnies，an uncontrollable，natural state of great pleasure. Grinnies are shown on the outside by sparkling eyes and a wide，wide smile－not just any smile，but one that shows the teeth and stretches the mouth to its limits. A person experiencing the grinnies appears to be all mouth. On the inside grinnies are characterized by a feeling of joyful anxiety. Grinnies usually last just a few seconds，but they can come and go. Sometimes，when life seems just perfect，I have occasional attacks of the grinnies for a whole day.
The term originated in my mother's family. Her younger sister，Rose，who had deep dimples(酒窝)，often expressed her pleasure with such a grin that the dimples appeared to become permanent. When Rose was about four，she started explaining her funny look by saying，“I have the grinnies.” The term caught on，and it has been an important word in our family now for two generations.
The occasion doesn't matter. Anything can bring on the  grinnies－just so long as one feels great delight. When my brother finally rode his bicycle－without training wheels－from our house to the corner and back，he came home with the grinnies. When I was little，my mother's announcement that we would have homemade ice cream for dessert always gave me the grinnies. My father had the grinnies when I was chosen to make  a  speech  at  the  endofschoolyear  ceremony. Grinnies can be brought on by a good meal，a sense of pride，a new friend，a telephone call from someone special，an achievement. Or sometimes one gets the grinnies for no reason at all：just a sudden sense of happiness can bring on a case. Whatever brings them on，an attack of the grinnies is among life's greatest pleasures.
In fact，now when I look back on the experience，I feel sorry for my seventhgrade teacher. I think it's a pity that she didn't know the word grinnies，It's such a useful term for saying，“I'm really，really pleased！”
After the writer was twelve years old，she________.

A．thought everyone knew the meaning of “grinnies”

B．equaled “grinnies” to bath or chocolate in meaning

C．got to know “grinnies” was used only inside her family

D．discovered the word “grinnies” through her mother

When her English teacher called her name，the writer was________.

A．looking at the big “A” on the top of her paper

B．listening to her English teacher attentively

C．too happy to notice what was happening around her

D．busy rewriting her composition

According to the writer，the word “grinnies” originates from________.

A．her mother

B．her aunt

C．her brother

D．her father

The writer feels sorry for her seventhgrade  teacher because the teacher________.

A．had no pity on her students

B．should not have laughed at her

C．didn't have any luck to meet her parents

D．had no idea of what “grinnies” was

What method does the writer use to explain “grinnies”？

A．Cause and effect.

B．Examples.

C．Comparison and contrast.

D．Process.