下列各式一定成立的是[ ]
A．﹣（x﹣7）=﹣x﹣7
B．5x（x+7）=5x+7
C．﹣a+b=﹣（a﹣b）
D．﹣a﹣b=﹣（a﹣b）
答案：C
透热转气
Speaker A: I wonder if I could arrange a meeting with Mr. Jones this afternoon. Speaker B:______
A．Let me see. This afternoon is all hooked up.
B．Sorry. You should ask someone else.
C．Good．Mr. Jones will be glad to see you.
D．Yes, you can see him.
