已知x有两个平方根，且│x│=3，则x的值为 [ ]
A、9
B、3
C、-3
D、±3
答案：B
Each girl present at the party was wearing a flower in the hair, which__________their beauty.
A．added
B．added up
C．added to
D．added up to
完成基本呼叫所需的媒体资源由哪个设备进行播放控制？（）
A.Application Server
B.Media Server
C.Softswitch
D.MG
