完形填空（共20小题，每小题1.5分,满分30分）
阅读下面短文，掌握其大意，然后从1—20题各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项。
The simplest way to say it is this: I believe in my mother. My __1_ began when I was just a kid．I __2__ becoming a doctor.
My mother was a domestic．Through her work, she observed that __3__ people spent a lot more time reading than they __4__ watching television. She announced that my brother and I _5__ watch two to three pre-selected TV programs during the week. With our free time, we had to read two books each from the Detroit Public Library and __6__ her written book reports. She would mark them up with check marks and highlights. Years later we realized her marks were a _7__. My mother was illiterate.
When I entered high school I was a(n) __8__, but not for long. I wanted the fancy clothes. I wanted to _9__ the guys. I went from being an A-student to a B-student to a C-student. One night my mother came home from _10__ her various jobs and I complained about not having enough Italian knit shirts. She said, “Okay, I'll give you all the money I make this week scrubbing floors and cleaning bathrooms, and you can buy _11_ food and pay the bills. With everything __12_, you can have all the Italian knit shirts you want.” I was very __13__ with that arrangement but once I got through allocating money, there was __14__ left. I realized my mother was a financial genius to be able to __15__ our heads and any kind of food on the table, __16_ buy clothes. I also realized that immediate satisfaction wasn't going to get me anywhere. Success required intellectual preparation. I went back to my __17__ and became an A-student again, and eventually I __08__ my dream and I became a doctor.
My story is really my mother's story—a woman with __19__ formal education or property who used her position as a parent to change the lives of many people around the globe. There is no job __20__ than parenting. This I believe.
1．A．belief B．work C．education D．promise
2．A．majored in B．got used to C．dreamed of D．got tired of
3．A．lazy B．easy-going C．successful D．reliable
4．A．spent B．paid C．took D．did
5．A．could only B．could not C．must not D．should often
6．A．read to B．present to C．teach D．explain to
7．A．joke B．means C．tool D．trick
8．A．A-student B．B-student C．C-student D．D-student
9．A．get rid of B．hang out with C．break away from D．keep in touch with
10．A．making B．stopping C．working D．getting
11．A．your brother B．yourself C．your sister D．the family
12．A．left over B．paid off C．used up D．carried out
13．A．angry B．pleased C．disappointed D．bored
14．A．anything B．everything C．something D．nothing
15．A．put an idea into B．gave an impression on
C．keep a roof over D．have eyes in the back of
16．A．let alone B．let out C．let in D．leave alone
17．A．guys B．mother C．studies D．play
18．A．made B．fulfilled C．changed D．tried
19．A．little B．much C．few D．high
20．A．more interesting B．less important C．more important D．less interesting
中，仅在第Ⅱ象限存在沿
轴正方向的匀强电场，一质量为
，电荷量为
，可视为质点的带正电粒子（重力不计）从
处的M点，以初速度
垂直于
轴上
处的P点进入第I象限。
向射出磁场。求所知磁场区域的半径。要求；磁场区域的边界过坐标原点，圆心在
