A:伽利略的理想实验是没有事实依据的凭空想象的实验
B:伽利略以事实为依据,通过假设、推理得出力不是维持物体运动状态的原因
C:笛卡尔指出:一切物体总保持匀速直线运动状态或静止状态,除非作用在它上面的力迫使它改变这种状态
D:牛顿第一定律与牛顿第二定律一样,都可通过实验直接检验
请和你的同学一起讨论讨论,找出答案。
Tom, Sam, Jim and Jack live in a building of four floors. They live on different floors. They have different jobs―an engineer, a worker, a teacher and a doctor. Tom lives above Sam, but below(在下面) Jim. Jack lives on the third floor. The doctor lives above the teacher, but below the worker. The engineer lives on the ground floor. What are their jobs? Which floor does each of them live on?
下面的几何体中,俯视图为三角形的是( )