A:电压表V并联在R1两端,滑片P由a端向b端移动
B:电压表V并联在R1两端,滑片P由b端向a端移动
C:电压表V并联在R2两瑞,滑片P由a端向b端移动
D:电压表V并联在R2两瑞,滑片P由b端向a端移动
电影院呈阶梯或下坡形状的主要原因是( )
湖面如镜,划桨泛舟.以划船的人为参照物,小船是____ 的;水鸟掠过湖面时,翅膀上方空气流速____ (选填“大于”、“小于”或“等于”)下方,翅膀上下表面存在压强差,形成升力.
找出相对应的答语把字母序号填空。
① How heavy are you? ____ A. They are Size 39.
② How tall are you? ____ B. I'm 15 years old.
③ How old are you? ____ C. I'm 45 kg.
④ What size are your shoes?____ D. I'm 158cm tall.
⑤ How long are your bed?____ E. It is 200cm.