【简答题】A. classification B. compare and contrastC. process ysisD. cause and effect E. problem and solution4. In recent decades, cities have grown so large that now about 50% of the Earth's pop...
【简答题】A. classification B. compare and contrastC. process ysisD. cause and effect E. problem and solution3. To pick the best restaurant for that romantic night out, a number of questions must...
【单选题】( 多选 ) (2018· 山西省长治、运城、大同、朔州、阳泉五地市联考 ) 下列说法正确的是 ( ) A. 日光灯是紫外线的荧光效应的应用 B. 单摆在做受迫振动时,它的周期等于单摆的固有周期 C. 机械波从一种介质进入另一种介质后,它的频率保持不变 D. 麦克斯韦第一次用实验证实了电磁波的存在 E. 弹簧振子做简谐振动时,振动系统的势能与动能之和保持不变