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如图(a)所示,水平放置的平行金属板AB间的距离d=0.1m,板长L=0.3m,在金属板的左端竖直放置一带有小孔的挡板,小孔恰好位于AB板的正中间,距金属板右端x=0.5m处竖直放置一足够大的荧光屏,现在AB板间加如图(b)所示的方波形电压,已知U0=1.0×102V,在挡板的左侧,有大量带正电的相同粒子以平行于金属板方向的速度持续射向挡板,粒子的质量m=1.0×107kg,电荷量q=1.0×102C,速度大小均为v0=1.0×104m/s,带电粒子的重力不计,则:

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根据短文内容,从短文后面的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    What should you think about in trying to find your career(职业)? You are probably better at some school subjects than others. ____ A boy who is good at mathematics can use that in an engineering career. ____ So it is important to do well at school. On the other hand, you may not have any specially strong or weak subjects but your records show a general satisfactory standard. ____ Knowledge of history is not required for most jobs but if history is one of your good subjects you will have learned to remember facts and details. This is an ability that can be useful in many jobs.

    ____ If nothing else, you may have learned how to get to work on time, to follow instructions and to get on with older workers. Just as important, you may become interested in a particular industry or career you see from the inside in a part-time job.

    Facing your weak points is also part of knowing yourself. ____ Your school record, for instance, may not be too good, yet it is an important part of your background. You should not be apologetic about it but instead recognize that you will have a chance of a fresh start at work.

A. It is better to face any weaknesses than to pretend they do not exist.

B. A girl who spells well and likes English may be good at office work.

C. He may do well in his future work.

D. Although not all subjects can be used directly in a job, they may have indirect value.

E. Your school must have taught you the skills.

F. These may show strengths (优势) that you can use in your work.

G. If you have had a part-time job on Saturday or in the summer, think what you gained from it.