《江苏省“十二五”科技发展规划》指出，到2015年，自主创新将成为江苏经济社会发展的主要推动力，其中，全社会研发投入占地区生产总值的比重达2
One dark and stormy night, an elderly man and his wife entered the hall of a small hotel in Philadelphia, hoping to get shelter for the night. The clerk, a friendly man with a beautiful smile, explai
71. The school rules that no child shall be allowed out of school during the day, unless _____(陪伴) by parents. 72. We want to make sure that our food supply is _____ _ (充裕)for all of us.
将KOH和Ca（OH）2的混合物1.3 g全部溶于一定量水中，配成稀溶液，再缓缓通入足量的CO2气体。 （1）当生成沉淀的质量刚好最大时，消耗CO2的体积224 mL（
下列说法中，不正确的是（ ）A．入射角是00，反射角也是00B．入射角增加150，反射角也增加150C．入射光线靠拢法线，反射光线也靠拢法线 D．入射
下列资源属于可再生资源的是（ ） A．石油 B．铝土矿 C．水 D．天然气
While building a tunnel through the mountain, _____. A. an underground lake was discovered B. workers discovered an underground lake C. there was an underground lak
如图所示，位于同一水平面内的、两根平行的光滑金属导轨，处在匀强磁场中，磁场方向垂直于导轨所在平面，导轨的一端与一电阻相连；具有一定质
