补全对话。
Anna: ____.
John: ____. Can I have a look?
Anna: ____. Here you are.
John: ____.
John: You are welcome.
A. Sure!
B. I have a nice cat.
C. Oh, really?
D. Thank you.
E. Oh! It's nice. I like it.
(3x+2)(﹣x4+3x5)+(3x+2)(﹣2x4+x5)+(x+1)(3x4﹣4x5)与下列哪一个式子相同( )
测量小灯泡的电功率实验(小灯泡额定电压2.5V)