读我国东部某地区示意图，判断下列说法正确的是（    ）。  

C

    One of the easiest ways to keep fit is to do jogging. Jogging is the name for a very gentle(舒缓的) running-it is just a little faster than walking.

    Start slow joging 20 meters , then walk 20 meters. Little by little , if you are not feeling very tired , you may do more jogging and less walking . Finally , jog the whole way . It will be easy for you to start jogging for 15 minutes twice a week , slowly, increase this to 20—30 minutes every day .The longer you join in jogging , the more you enjoy it and the healthier you will become . Some people like jogging alone , and others enjoy doing it with friends . Jogging in groups makes more people keener(热心的)，because you just can not stay in bed while there is a group of friends waiting outside.

    If you want to start jogging , prepare a pair of comfortable shoes and a determined mind.

作法：（1）作射线O'A'.（2）以点O为圆心，以任意长为半径作弧，交OA于C，交OB于D．（3）以点O'为圆心，以OC长为半径作弧，交O’A'于C'．（4）以点C'为圆心，以CD长为半径作弧，交前弧于D'．（5）经过点D'作射线O'B'．∠A'D'B'就是所求的角．

这个作图是（      ）

国家实施“少数民族扶贫攻坚计划”，积极帮助少数民族地区发展经济，逐步缩小地区发展差距。这些做法表明了（   ）