The children had to repeat that story twice,________they?
A:didn't
B:hadn't
C:did
D:had
在如图所示方格纸中,已知△DEF是由△ABC经相似变换所得的像,那么△DEF的每条边都扩大到原来的____ 倍.
下列地点中,属于西半球和南半球的是( )
He ____ (write) a letter to his parents last week.