如果a＜b，那么下列结论一定正确的是[ ]
A.a-3＞b-3
B.3-a＞3-b
C.ac2＜bc2
D.2a2＜2b2
答案：B
火眼金睛改错字。
秀满花纹( ) 呜声清脆( )
透亮零活( ) 难以逃拖( )
There was a fire last night and more than one house _____ burnt down in the fire.
A．has been
B．was
C．have been
D．were
