【单选题】太阳能汽车是靠太阳能来驱动的汽车,当太阳光照射到汽车上方的光电板时,光电板中产生的电流经电动机带动汽车前进.设汽车在平直的公路上由静止开始匀加速行驶,经过时间 t ,速度为 v 时功率达到额定功率,并保持不变.之后汽车又继续前进了距离 s ,达到最大速度 v max .设汽车质量为 m ,运动过程中所受阻力恒为 f ,则下列说法正确的是 ( )
【简答题】Bob Smith is a little boy. On the first day at school, his teacher, Ms. Green, teaches him three words—you, he and I. Then the teacher says, “I am your teacher. You are my student. He is your classmat...