A:x2+5x-1=x(x+5)-1
B:x2-4+3x=(x+2)(x-2)+3x
C:x2-9=(x+3)(x-3)
D:(x+2)(x-2)=x2-4
⑴How old are you?____ A. Thank you.
⑵This is for you.____ B. Yes, it is.
⑶Don't shout here.____ C. I'm six.
⑷Where's my schoolbag?____ D. I'm sorry.
⑸Is that your pencil?____ E. It's under the desk.
下列化学方程式能正确表示所述内容的是( )
把右边的立体图形移到虚线的地方。