下列比例当中表示放大比例的是()
A.1:1
B.2:1
C.1:2
参考答案:B
— Thomas didn't come to school for the meeting, did he?
— No. He ____. The meeting had been cancelled.[ ]
A. shouldn't have come
B. should not come
C. didn't need to come
D. wouldn't have come
MMS是封装在SMPP协议之上的高层应用程序。