如图所示，电源电压恒定．闭合开关S₁、S₂，电压表示数为9V，电流表示数为1.5A；断开开关S₂，电压表示数为6V．则R₁和R₂的阻值分别是（）

    Are you facing a situation that looks impossible to fix?

    In 1969,the pollution was terrible along the Cuyahoga River Cleveland, Ohio. It____(be) unimaginable that it could ever be cleaned up. The river was so polluted that it____(actual) caught fire and burned. Now, years later, this river is one of____most outstanding（杰出的）examples of environmental cleanup.

    But the river wasn't changed in a few days____even a few months. It took years of work ____(reduce) the industrial pollution and clean the water. Finally, that hard work paid off and now the water in the river is____(clean) than ever.

    Maybe you are facing an impossible situation. Maybe you leave a habit____is driving your family crazy. Possibly you drink too much or don't know how to control your credit card use. When you face such an impossible situation, don't you want a quick fix and something to change immediately?

    While there are____(amaze) stories of instant transformation, for most of us the____(change) are gradual and require a lot of effort and work, like cleaning up a polluted river. Just be ____(patience).

写出下列词语的近义词

①漫天飞舞的樱花仿佛____洁白的雪精灵在空中欢快地跳动。

②狗不理包子不仅在中国家喻户晓，而且天下闻名____。

③王大爷虽然年纪大,可眼睛却很好使,看东西清清楚楚____。