2015年10月，中国女科学家屠呦呦获得诺贝尔医学奖。屠呦呦从中医古籍里得到启发，通过对提取方法的改进及多次试验，首先发现中药青蒿的提取物有高效抑制疟原虫的成分，取得研究突破，引发世界广泛关注。这说明（     ）

①中华文化源远流长、博大精深

②传统文化具有包容性

③立足于社会实践基础上的医药文化创新具有重要社会和文化意义

④推进医药文化发展创新必须面向世界、博采众长才能成功

甲、乙两名棋手比赛正在进行中，甲必须再胜2盘才最后获胜，乙必须再胜3盘才最后获胜，若甲、乙两人每盘取胜的概率都是$\frac{1}{2}$，则甲最后获胜的概率是（  ）

If you want to watch TV, you should____(finish) your homework first.

                                     C

    People call the Winter Olympics the White Olympics. At this time, they publish(发行) many stamps to mark(标志) the great games. The first stamps came out on January 25th, 1932 in the United States for the 3rd White Olympics. From then on, publishing stamps during the White Olympics became a rule.

    During the 4th Winter Olympics, people published a group of stamps in November 1936. They drew five rings of Olympics. It was the first time that the rings appeared(出现) on the stamps of the White Olympics.

    In the 1950s，the stamps of this kind became more colorful. When the White Olympics came, the host countries as well as non-host countries published stamps to mark those games. China also published four stamps in February 1980 when the Chinese sportsmen began to take part in the White Olympics.

    In Asia, Japan was the only country to hold the White Olympics. They sold 14,500 million stamps during the Olympics.

    People drew different kinds of sports on these small stamps, and they enjoyed the wonderful sports and some famous players.